core: Move core.oat bootjar definitions into envsetup.mk

TARGET_CORE_JARS and HOST_CORE_JARS define the minimal bootclasspath jars necessary to run
with dalvikvm/art.

Also refactor PRODUCT_BOOT_JARS in core-tiny.mk and core-minimal.mk to reuse TARGET_CORE_JARS.
The above variables can be used from scripts with get_build_var from envsetup.sh

  $> get_build_var TARGET_CORE_JARS
  <prints list of core jars>

(These changes are required to figure out what --bootclasspath_entry to pass to desugar).

Bug: 36902714
Test: make -j32 build-art-host build-art-target
Test: lunch aosp_angler-userdebug && make -j32
Test: make -j32 PRODUCT-sdk_google_aw_x86-sdk
Change-Id: If12569719343bfbba20c1cda9a5302ab541dbfc6
(cherry picked from commit f33a96c07f)

core/envsetup.mk

@@ -190,6 +190,13 @@ _vendor_path_placeholder := ||VENDOR-PATH-PH||
 TARGET_COPY_OUT_VENDOR := $(_vendor_path_placeholder)
 ###########################################
 
+#################################################################
+# Set up minimal BOOTCLASSPATH list of jars to build/execute
+# java code with dalvikvm/art.
+TARGET_CORE_JARS := core-oj core-libart conscrypt okhttp bouncycastle apache-xml
+HOST_CORE_JARS := $(addsuffix -hostdex,$(TARGET_CORE_JARS))
+#################################################################
+
 # Read the product specs so we can get TARGET_DEVICE and other
 # variables that we need in order to locate the output files.
 include $(BUILD_SYSTEM)/product_config.mk

target/product/core_minimal.mk

@@ -98,20 +98,19 @@ PRODUCT_COPY_FILES += \
     frameworks/native/data/etc/android.software.preview_sdk.xml:system/etc/permissions/android.software.preview_sdk.xml
 endif
 
+ifeq ($(TARGET_CORE_JARS),)
+$(error TARGET_CORE_JARS is empty; cannot initialize PRODUCT_BOOT_JARS variable)
+endif
+
 # The order of PRODUCT_BOOT_JARS matters.
 PRODUCT_BOOT_JARS := \
-    core-oj \
+    $(TARGET_CORE_JARS) \
-    core-libart \
-    conscrypt \
-    okhttp \
     legacy-test \
-    bouncycastle \
     ext \
     framework \
     telephony-common \
     voip-common \
     ims-common \
-    apache-xml \
     org.apache.http.legacy.boot \
     android.hidl.base-V1.0-java \
     android.hidl.manager-V1.0-java

target/product/core_tiny.mk

@@ -85,20 +85,19 @@ PRODUCT_PACKAGES += \
     logd \
     wifi-service
 
+ifeq ($(TARGET_CORE_JARS),)
+$(error TARGET_CORE_JARS is empty; cannot initialize PRODUCT_BOOT_JARS variable)
+endif
+
 # The order matters
 PRODUCT_BOOT_JARS := \
-    core-oj \
+    $(TARGET_CORE_JARS) \
-    core-libart \
-    conscrypt \
-    okhttp \
     legacy-test \
-    bouncycastle \
     ext \
     framework \
     telephony-common \
     voip-common \
     ims-common \
-    apache-xml \
     nullwebview \
     org.apache.http.legacy.boot \
     android.hidl.base-V1.0-java \

target/product/runtime_libart.mk

@@ -16,15 +16,14 @@
 
 # Provides a functioning ART environment without Android frameworks
 
+ifeq ($(TARGET_CORE_JARS),)
+$(error TARGET_CORE_JARS is empty; cannot update PRODUCT_PACKAGES variable)
+endif
+
 # Minimal boot classpath. This should be a subset of PRODUCT_BOOT_JARS, and equivalent to
 # TARGET_CORE_JARS.
 PRODUCT_PACKAGES += \
-    apache-xml \
+    $(TARGET_CORE_JARS)
-    bouncycastle \
-    core-oj \
-    core-libart \
-    conscrypt \
-    okhttp \
 
 # Additional mixins to the boot classpath.
 PRODUCT_PACKAGES += \