Allow locally disabling R8

Bug: 74746744
Test: m checkbuild
Change-Id: I5741f15821cf8de5df494ed8ad31d32a44657514
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index fc6b83c..8488858 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -264,6 +264,7 @@
 LOCAL_UNINSTALLABLE_MODULE:=
 LOCAL_UNSTRIPPED_PATH:=
 LOCAL_USE_AAPT2:=$(USE_AAPT2)
+LOCAL_USE_R8:=
 LOCAL_USE_VNDK:=
 LOCAL_VENDOR_MODULE:=
 LOCAL_VTSC_FLAGS:=
diff --git a/core/java.mk b/core/java.mk
index dc20444..097f52c 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -15,6 +15,10 @@
 endif # !PDK_JAVA
 endif #PDK
 
+ifndef LOCAL_USE_R8
+LOCAL_USE_R8 := $(USE_R8)
+endif
+
 LOCAL_NO_STANDARD_LIBRARIES:=$(strip $(LOCAL_NO_STANDARD_LIBRARIES))
 LOCAL_SDK_VERSION:=$(strip $(LOCAL_SDK_VERSION))
 
@@ -687,9 +691,9 @@
 endif # LOCAL_INSTRUMENTATION_FOR
 
 proguard_flag_files := $(addprefix $(LOCAL_PATH)/, $(LOCAL_PROGUARD_FLAG_FILES))
-ifeq ($(USE_R8),true)
+ifeq ($(LOCAL_USE_R8),true)
 proguard_flag_files += $(addprefix $(LOCAL_PATH)/, $(LOCAL_R8_FLAG_FILES))
-endif # USE_R8
+endif # LOCAL_USE_R8
 LOCAL_PROGUARD_FLAGS += $(addprefix -include , $(proguard_flag_files))
 
 ifdef LOCAL_TEST_MODULE_TO_PROGUARD_WITH
@@ -712,7 +716,7 @@
 endif
 
 ifneq ($(filter obfuscation,$(LOCAL_PROGUARD_ENABLED)),)
-ifneq ($(USE_R8),true)
+ifneq ($(LOCAL_USE_R8),true)
   $(full_classes_proguard_jar): .KATI_IMPLICIT_OUTPUTS := $(proguard_dictionary)
 else
   $(built_dex_intermediate): .KATI_IMPLICIT_OUTPUTS := $(proguard_dictionary)
@@ -720,7 +724,7 @@
 endif
 
 # If R8 is not enabled run Proguard.
-ifneq ($(USE_R8),true)
+ifneq ($(LOCAL_USE_R8),true)
 # Changes to these dependencies need to be replicated below when using R8
 # instead of Proguard + dx.
 $(full_classes_proguard_jar): PRIVATE_PROGUARD_INJAR_FILTERS := $(proguard_injar_filters)
@@ -728,10 +732,10 @@
 $(full_classes_proguard_jar): PRIVATE_PROGUARD_FLAGS := $(legacy_proguard_flags) $(common_proguard_flags) $(LOCAL_PROGUARD_FLAGS)
 $(full_classes_proguard_jar) : $(full_classes_pre_proguard_jar) $(extra_input_jar) $(my_proguard_sdk_raise) $(common_proguard_flag_files) $(proguard_flag_files) $(legacy_proguard_lib_deps) | $(PROGUARD)
 	$(call transform-jar-to-proguard)
-else # !USE_R8
+else # !LOCAL_USE_R8
 # Running R8 instead of Proguard, proguarded jar is actually the pre-Proguarded jar.
 full_classes_proguard_jar := $(full_classes_pre_proguard_jar)
-endif # !USE_R8
+endif # !LOCAL_USE_R8
 
 else  # LOCAL_PROGUARD_ENABLED not defined
 proguard_flag_files :=
@@ -743,7 +747,7 @@
 
 my_r8 :=
 ifdef LOCAL_PROGUARD_ENABLED
-ifeq ($(USE_R8),true)
+ifeq ($(LOCAL_USE_R8),true)
 # These are the dependencies for the proguarded jar when running
 # Proguard + dx. They are used for the generated dex when using R8, as
 # R8 does Proguard + dx
@@ -753,7 +757,7 @@
 $(built_dex_intermediate): PRIVATE_PROGUARD_FLAGS := $(legacy_proguard_flags) $(common_proguard_flags) $(LOCAL_PROGUARD_FLAGS)
 $(built_dex_intermediate) : $(full_classes_proguard_jar) $(extra_input_jar) $(my_support_library_sdk_raise) $(common_proguard_flag_files) $(proguard_flag_files) $(legacy_proguard_lib_deps) $(R8_COMPAT_PROGUARD)
 	$(transform-jar-to-dex-r8)
-endif # USE_R8
+endif # LOCAL_USE_R8
 endif # LOCAL_PROGUARD_ENABLED
 
 ifndef my_r8