packages/services/Car: Set LOCAL_SDK_VERSION where possible.

This change sets LOCAL_SDK_VERSION for all packages where
this is possible without breaking the build, and
LOCAL_PRIVATE_PLATFORM_APIS := true otherwise.

Setting one of these two will be made required soon, and this
is a change in preparation for that. Not setting LOCAL_SDK_VERSION
makes the app implicitly depend on the bootclasspath, which is
often not required. This change effectively makes depending on
private apis opt-in rather than opt-out.

Test: make relevant packages
Bug: 73535841
Change-Id: I1e77ed30aa2b67a6b8640a23fc42c28b0445bf29
diff --git a/tests/EmbeddedKitchenSinkApp/Android.mk b/tests/EmbeddedKitchenSinkApp/Android.mk
index 64084b9..0833915 100644
--- a/tests/EmbeddedKitchenSinkApp/Android.mk
+++ b/tests/EmbeddedKitchenSinkApp/Android.mk
@@ -29,6 +29,7 @@
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
 LOCAL_PACKAGE_NAME := EmbeddedKitchenSinkApp
+LOCAL_PRIVATE_PLATFORM_APIS := true
 
 LOCAL_MODULE_TAGS := optional