Properly define angle.mk

Previously we used USE_ANGLE to determine whether the build should include
ANGLE drivers, this patch consolidates that into a separate Makefile.

Bug: b/270994705
Test: atest CtsAngleIntegrationHostTestCases
Change-Id: I4d7ffb869ced219009446d907230178e4b940157

core/main.mk

@@ -320,10 +320,6 @@ ADDITIONAL_VENDOR_PROPERTIES += \
     ro.board.platform=$(TARGET_BOARD_PLATFORM) \
     ro.hwui.use_vulkan=$(TARGET_USES_VULKAN)
 
-# Set ro.gfx.angle.supported based on if ANGLE is installed in vendor partition
-ADDITIONAL_VENDOR_PROPERTIES += \
-    ro.gfx.angle.supported=$(USE_ANGLE)
-
 ifdef TARGET_SCREEN_DENSITY
 ADDITIONAL_VENDOR_PROPERTIES += \
     ro.sf.lcd_density=$(TARGET_SCREEN_DENSITY)

target/product/angle.mk

@@ -0,0 +1,26 @@
+#
+# Copyright 2023 The Android Open-Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# To include ANGLE drivers into the build, add
+# $(call inherit-product, $(SRC_TARGET_DIR)/product/angle.mk) to the Makefile.
+
+PRODUCT_PACKAGES := \
+    libEGL_angle \
+    libGLESv1_CM_angle \
+    libGLESv2_angle
+
+# Set ro.gfx.angle.supported based on if ANGLE is installed in vendor partition
+PRODUCT_VENDOR_PROPERTIES := ro.gfx.angle.supported=true