Use prebuilt android.test.base.jar for app builds

(cherry picked from commit 1f090a8d66126a936e40f0e872c5fe5b655fa335)

Bug: 30188076
Test: make checkbuild
Change-Id: I09a70f3e79d0935394332870613b96c653af5e85
Merged-In: I1d7e705baf5728e7a034f3bd32746de3a1d3cd78
diff --git a/test-base/Android.mk b/test-base/Android.mk
index 25c3d76..8613854 100644
--- a/test-base/Android.mk
+++ b/test-base/Android.mk
@@ -16,8 +16,11 @@
 
 LOCAL_PATH:= $(call my-dir)
 
-# Generate the stub source files for legacy.test.stubs
-# ====================================================
+# For unbundled build we'll use the prebuilt jar from prebuilts/sdk.
+ifeq (,$(TARGET_BUILD_APPS)$(filter true,$(TARGET_BUILD_PDK)))
+
+# Generate the stub source files for android.test.base.stubs
+# ==========================================================
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := \
@@ -107,6 +110,8 @@
 	@echo Copying removed.txt
 	$(hide) $(ACP) $(ANDROID_TEST_BASE_OUTPUT_REMOVED_API_FILE) $(ANDROID_TEST_BASE_REMOVED_API_FILE)
 
+endif  # not TARGET_BUILD_APPS not TARGET_BUILD_PDK=true
+
 ifeq ($(HOST_OS),linux)
 # Build the legacy-performance-test-hostdex library
 # =================================================