dalvik sysprop settings are optional

dalvik sysprop settings in these mk files are changed to optional ones
using the new 'a ?= b' syntax, to better express the intent that these
provides safe default values which will be used when they are set in
a product-specific mk file.

This is also in preparation for
I9c073a21c8257987cf2378012cadaeeeb698a4fb, which when lands will
prohibit duplicated sysprop assignments.

Bug: 117892318
Bug: 158735147
Test: m

Exempt-From-Owner-Approval: cherry-pick from internal

Merged-In: Ia3528c0c2f9715ff10b85b549d739c9263ab6a7e
(cherry picked from commit 04f86d1cff620d3e7d1792795639ab0ca7edb715)
Change-Id: Ia3528c0c2f9715ff10b85b549d739c9263ab6a7e
diff --git a/build/phone-hdpi-512-dalvik-heap.mk b/build/phone-hdpi-512-dalvik-heap.mk
index 102c3f1..f9a12ef 100644
--- a/build/phone-hdpi-512-dalvik-heap.mk
+++ b/build/phone-hdpi-512-dalvik-heap.mk
@@ -17,10 +17,10 @@
 # Provides overrides to configure the Dalvik heap for a standard high density
 # phone with around 512MB total RAM.
 
-PRODUCT_PROPERTY_OVERRIDES += \
-    dalvik.vm.heapstartsize=5m \
-    dalvik.vm.heapgrowthlimit=48m \
-    dalvik.vm.heapsize=128m \
-    dalvik.vm.heaptargetutilization=0.75 \
-    dalvik.vm.heapminfree=512k \
-    dalvik.vm.heapmaxfree=2m
+PRODUCT_VENDOR_PROPERTIES += \
+    dalvik.vm.heapstartsize?=5m \
+    dalvik.vm.heapgrowthlimit?=48m \
+    dalvik.vm.heapsize?=128m \
+    dalvik.vm.heaptargetutilization?=0.75 \
+    dalvik.vm.heapminfree?=512k \
+    dalvik.vm.heapmaxfree?=2m
diff --git a/build/phone-hdpi-dalvik-heap.mk b/build/phone-hdpi-dalvik-heap.mk
index cc0ac90..71cce74 100644
--- a/build/phone-hdpi-dalvik-heap.mk
+++ b/build/phone-hdpi-dalvik-heap.mk
@@ -16,9 +16,9 @@
 
 # Provides overrides to configure the Dalvik heap for a standard high density phone.
 
-PRODUCT_PROPERTY_OVERRIDES += \
-    dalvik.vm.heapstartsize=5m \
-    dalvik.vm.heapsize=32m \
-    dalvik.vm.heaptargetutilization=0.75 \
-    dalvik.vm.heapminfree=512k \
-    dalvik.vm.heapmaxfree=2m
+PRODUCT_VENDOR_PROPERTIES += \
+    dalvik.vm.heapstartsize?=5m \
+    dalvik.vm.heapsize?=32m \
+    dalvik.vm.heaptargetutilization?=0.75 \
+    dalvik.vm.heapminfree?=512k \
+    dalvik.vm.heapmaxfree?=2m
diff --git a/build/phone-xhdpi-1024-dalvik-heap.mk b/build/phone-xhdpi-1024-dalvik-heap.mk
index 221227d..a522a7d 100644
--- a/build/phone-xhdpi-1024-dalvik-heap.mk
+++ b/build/phone-xhdpi-1024-dalvik-heap.mk
@@ -16,10 +16,10 @@
 
 # Provides overrides to configure the Dalvik heap for a xhdpi phone
 
-PRODUCT_PROPERTY_OVERRIDES += \
-    dalvik.vm.heapstartsize=8m \
-    dalvik.vm.heapgrowthlimit=96m \
-    dalvik.vm.heapsize=256m \
-    dalvik.vm.heaptargetutilization=0.75 \
-    dalvik.vm.heapminfree=512k \
-    dalvik.vm.heapmaxfree=8m
+PRODUCT_VENDOR_PROPERTIES += \
+    dalvik.vm.heapstartsize?=8m \
+    dalvik.vm.heapgrowthlimit?=96m \
+    dalvik.vm.heapsize?=256m \
+    dalvik.vm.heaptargetutilization?=0.75 \
+    dalvik.vm.heapminfree?=512k \
+    dalvik.vm.heapmaxfree?=8m
diff --git a/build/phone-xhdpi-2048-dalvik-heap.mk b/build/phone-xhdpi-2048-dalvik-heap.mk
index 7ccfc13..f38d2f2 100644
--- a/build/phone-xhdpi-2048-dalvik-heap.mk
+++ b/build/phone-xhdpi-2048-dalvik-heap.mk
@@ -17,10 +17,10 @@
 # Provides overrides to configure the Dalvik heap for a 2GB phone
 # 192m of RAM gives enough space for 5 8 megapixel camera bitmaps in RAM.
 
-PRODUCT_PROPERTY_OVERRIDES += \
-    dalvik.vm.heapstartsize=8m \
-    dalvik.vm.heapgrowthlimit=192m \
-    dalvik.vm.heapsize=512m \
-    dalvik.vm.heaptargetutilization=0.75 \
-    dalvik.vm.heapminfree=512k \
-    dalvik.vm.heapmaxfree=8m
+PRODUCT_VENDOR_PROPERTIES += \
+    dalvik.vm.heapstartsize?=8m \
+    dalvik.vm.heapgrowthlimit?=192m \
+    dalvik.vm.heapsize?=512m \
+    dalvik.vm.heaptargetutilization?=0.75 \
+    dalvik.vm.heapminfree?=512k \
+    dalvik.vm.heapmaxfree?=8m
diff --git a/build/phone-xhdpi-4096-dalvik-heap.mk b/build/phone-xhdpi-4096-dalvik-heap.mk
index 2b84841..a6ff5a8 100644
--- a/build/phone-xhdpi-4096-dalvik-heap.mk
+++ b/build/phone-xhdpi-4096-dalvik-heap.mk
@@ -16,10 +16,10 @@
 
 # Provides overrides to configure the Dalvik heap for a 4GB phone
 
-PRODUCT_PROPERTY_OVERRIDES += \
-    dalvik.vm.heapstartsize=8m \
-    dalvik.vm.heapgrowthlimit=192m \
-    dalvik.vm.heapsize=512m \
-    dalvik.vm.heaptargetutilization=0.6 \
-    dalvik.vm.heapminfree=8m \
-    dalvik.vm.heapmaxfree=16m
+PRODUCT_VENDOR_PROPERTIES += \
+    dalvik.vm.heapstartsize?=8m \
+    dalvik.vm.heapgrowthlimit?=192m \
+    dalvik.vm.heapsize?=512m \
+    dalvik.vm.heaptargetutilization?=0.6 \
+    dalvik.vm.heapminfree?=8m \
+    dalvik.vm.heapmaxfree?=16m
diff --git a/build/phone-xhdpi-6144-dalvik-heap.mk b/build/phone-xhdpi-6144-dalvik-heap.mk
index 2bacc4a..f08830b 100644
--- a/build/phone-xhdpi-6144-dalvik-heap.mk
+++ b/build/phone-xhdpi-6144-dalvik-heap.mk
@@ -16,10 +16,10 @@
 
 # Provides overrides to configure the Dalvik heap for a 6GB phone
 
-PRODUCT_PROPERTY_OVERRIDES += \
-    dalvik.vm.heapstartsize=16m \
-    dalvik.vm.heapgrowthlimit=256m \
-    dalvik.vm.heapsize=512m \
-    dalvik.vm.heaptargetutilization=0.5 \
-    dalvik.vm.heapminfree=8m \
-    dalvik.vm.heapmaxfree=32m
+PRODUCT_VENDOR_PROPERTIES += \
+    dalvik.vm.heapstartsize?=16m \
+    dalvik.vm.heapgrowthlimit?=256m \
+    dalvik.vm.heapsize?=512m \
+    dalvik.vm.heaptargetutilization?=0.5 \
+    dalvik.vm.heapminfree?=8m \
+    dalvik.vm.heapmaxfree?=32m
diff --git a/build/tablet-10in-xhdpi-2048-dalvik-heap.mk b/build/tablet-10in-xhdpi-2048-dalvik-heap.mk
index 1721fcc..48c6ea6 100644
--- a/build/tablet-10in-xhdpi-2048-dalvik-heap.mk
+++ b/build/tablet-10in-xhdpi-2048-dalvik-heap.mk
@@ -16,10 +16,10 @@
 
 # Provides overrides to configure the Dalvik heap for a standard tablet device.
 
-PRODUCT_PROPERTY_OVERRIDES += \
-    dalvik.vm.heapstartsize=16m \
-    dalvik.vm.heapgrowthlimit=192m \
-    dalvik.vm.heapsize=512m \
-    dalvik.vm.heaptargetutilization=0.75 \
-    dalvik.vm.heapminfree=512k \
-    dalvik.vm.heapmaxfree=8m
+PRODUCT_VENDOR_PROPERTIES += \
+    dalvik.vm.heapstartsize?=16m \
+    dalvik.vm.heapgrowthlimit?=192m \
+    dalvik.vm.heapsize?=512m \
+    dalvik.vm.heaptargetutilization?=0.75 \
+    dalvik.vm.heapminfree?=512k \
+    dalvik.vm.heapmaxfree?=8m
diff --git a/build/tablet-7in-hdpi-1024-dalvik-heap.mk b/build/tablet-7in-hdpi-1024-dalvik-heap.mk
index 7fd34b5..d0027dc 100644
--- a/build/tablet-7in-hdpi-1024-dalvik-heap.mk
+++ b/build/tablet-7in-hdpi-1024-dalvik-heap.mk
@@ -16,10 +16,10 @@
 
 # Provides overrides to configure the Dalvik heap for a standard tablet device.
 
-PRODUCT_PROPERTY_OVERRIDES += \
-    dalvik.vm.heapstartsize=8m \
-    dalvik.vm.heapgrowthlimit=80m \
-    dalvik.vm.heapsize=384m \
-    dalvik.vm.heaptargetutilization=0.75 \
-    dalvik.vm.heapminfree=512k \
-    dalvik.vm.heapmaxfree=8m
+PRODUCT_VENDOR_PROPERTIES += \
+    dalvik.vm.heapstartsize?=8m \
+    dalvik.vm.heapgrowthlimit?=80m \
+    dalvik.vm.heapsize?=384m \
+    dalvik.vm.heaptargetutilization?=0.75 \
+    dalvik.vm.heapminfree?=512k \
+    dalvik.vm.heapmaxfree?=8m
diff --git a/build/tablet-7in-xhdpi-2048-dalvik-heap.mk b/build/tablet-7in-xhdpi-2048-dalvik-heap.mk
index e0f20c1..7c06b4b 100644
--- a/build/tablet-7in-xhdpi-2048-dalvik-heap.mk
+++ b/build/tablet-7in-xhdpi-2048-dalvik-heap.mk
@@ -16,10 +16,10 @@
 
 # Provides overrides to configure the Dalvik heap for a 320dpi 7" tablet device.
 
-PRODUCT_PROPERTY_OVERRIDES += \
-    dalvik.vm.heapstartsize=16m \
-    dalvik.vm.heapgrowthlimit=192m \
-    dalvik.vm.heapsize=512m \
-    dalvik.vm.heaptargetutilization=0.75 \
-    dalvik.vm.heapminfree=512k \
-    dalvik.vm.heapmaxfree=8m
+PRODUCT_VENDOR_PROPERTIES += \
+    dalvik.vm.heapstartsize?=16m \
+    dalvik.vm.heapgrowthlimit?=192m \
+    dalvik.vm.heapsize?=512m \
+    dalvik.vm.heaptargetutilization?=0.75 \
+    dalvik.vm.heapminfree?=512k \
+    dalvik.vm.heapmaxfree?=8m
diff --git a/build/tablet-dalvik-heap.mk b/build/tablet-dalvik-heap.mk
index f577fb8..1688665 100644
--- a/build/tablet-dalvik-heap.mk
+++ b/build/tablet-dalvik-heap.mk
@@ -16,10 +16,10 @@
 
 # Provides overrides to configure the Dalvik heap for a standard tablet device.
 
-PRODUCT_PROPERTY_OVERRIDES += \
-    dalvik.vm.heapstartsize=5m \
-    dalvik.vm.heapgrowthlimit=48m \
-    dalvik.vm.heapsize=256m \
-    dalvik.vm.heaptargetutilization=0.75 \
-    dalvik.vm.heapminfree=512k \
-    dalvik.vm.heapmaxfree=2m
+PRODUCT_VENDOR_PROPERTIES += \
+    dalvik.vm.heapstartsize?=5m \
+    dalvik.vm.heapgrowthlimit?=48m \
+    dalvik.vm.heapsize?=256m \
+    dalvik.vm.heaptargetutilization?=0.75 \
+    dalvik.vm.heapminfree?=512k \
+    dalvik.vm.heapmaxfree?=2m