Add legacy-test as replacement for core-junit

Statically includes core-junit-static into legacy-test target so
that legacy-test can be used in place of core-test. Once that
switch over has been done then android.test classes that are
being removed from the public API can be safely moved into here.

(cherry picked from commit bc90fcb983bb8d8066d50de90af5190a07c0a7f4)

Bug: 30188076
Test: make legacy-test and check contents of generated legacy-test artifacts
Change-Id: I7cdbeff5d95473ec2bfe6341d3957cf38d98e933

Android.mk

@@ -515,7 +515,7 @@ framework_res_R_stamp := \
 LOCAL_ADDITIONAL_DEPENDENCIES := $(framework_res_R_stamp)
 
 LOCAL_NO_STANDARD_LIBRARIES := true
-LOCAL_JAVA_LIBRARIES := core-oj core-libart conscrypt okhttp core-junit bouncycastle ext
+LOCAL_JAVA_LIBRARIES := core-oj core-libart conscrypt okhttp legacy-test bouncycastle ext
 
 LOCAL_STATIC_JAVA_LIBRARIES :=                          \
     framework-protos                                    \

legacy-test/Android.mk

@@ -0,0 +1,29 @@
+#
+# Copyright (C) 2016 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.
+#
+
+LOCAL_PATH:= $(call my-dir)
+
+# Build the legacy-test library
+# =============================
+# This contains the junit.framework classes that were in Android API level 25.
+include $(CLEAR_VARS)
+
+LOCAL_NO_STANDARD_LIBRARIES := true
+LOCAL_STATIC_JAVA_LIBRARIES := core-junit-static
+
+LOCAL_MODULE := legacy-test
+
+include $(BUILD_JAVA_LIBRARY)