Stubs required for javac to compile lambda code

In order for javac to compile code with (non-serializable) lambdas
the included classes are required. These are based on OpenJDK 8
source code which has then been stubbed. The stubs are only
required for build paths that use javac (e.g. javadoc) and
are not to be deployed to a device.

Bug: 26753820
(cherry-picked from commit 35eb86d88d048c5010ca406a8d543a54b84ca7b8)

Change-Id: I1de207b54865ded4c0582dd2f3c3f8f9bebda11f
diff --git a/JavaLibrary.mk b/JavaLibrary.mk
index bbe2345..4040359 100644
--- a/JavaLibrary.mk
+++ b/JavaLibrary.mk
@@ -81,7 +81,7 @@
 #
 
 include $(CLEAR_VARS)
-LOCAL_SRC_FILES := $(openjdk_java_files) $(non_openjdk_java_files) $(android_icu4j_src_files)
+LOCAL_SRC_FILES := $(openjdk_java_files) $(non_openjdk_java_files) $(android_icu4j_src_files) $(openjdk_lambda_stub_files)
 LOCAL_JAVA_RESOURCE_DIRS := $(core_resource_dirs) $(android_icu4j_resource_dirs)
 LOCAL_NO_STANDARD_LIBRARIES := true
 LOCAL_JAVACFLAGS := $(local_javac_flags)
@@ -212,7 +212,7 @@
 include $(BUILD_HOST_JAVA_LIBRARY)
 
 include $(CLEAR_VARS)
-LOCAL_SRC_FILES := $(non_openjdk_java_files) $(openjdk_java_files) $(android_icu4j_src_files)
+LOCAL_SRC_FILES := $(non_openjdk_java_files) $(openjdk_java_files) $(android_icu4j_src_files) $(openjdk_lambda_stub_files)
 LOCAL_JAVA_RESOURCE_DIRS := $(core_resource_dirs)
 LOCAL_NO_STANDARD_LIBRARIES := true
 LOCAL_JAVACFLAGS := $(local_javac_flags)