Prepare for removal of legacy-test from default targets

In preparation for removing junit classes from the Android API
the legacy-test target will be removed from the
TARGET_DEFAULT_JAVA_LIBRARIES. This change adds explicit
dependencies on junit and/or legacy-android-test to ensure that
modules will compile properly once it is removed.

Bug: 30188076
Test: make checkbuild
Merged-In: I84ed2bb7ea7c9cca241cc5ccac6ecf70521d8c88
Change-Id: Ifbc5f84c584dafd684de44702e6cba89f8642aa2
diff --git a/tests/unit/Android.mk b/tests/unit/Android.mk
index c7fca1f..5de3e01 100644
--- a/tests/unit/Android.mk
+++ b/tests/unit/Android.mk
@@ -6,7 +6,10 @@
 
 LOCAL_JAVA_LIBRARIES := android.test.runner
 
-LOCAL_STATIC_JAVA_LIBRARIES := android-support-test mockito-target
+LOCAL_STATIC_JAVA_LIBRARIES := \
+    android-support-test \
+    mockito-target \
+    legacy-android-test
 
 # Include all test java files.
 LOCAL_SRC_FILES := $(call all-java-files-under, src)