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
Change-Id: I395c0ab68270dec7863314fb215a68ed6c3941f6
diff --git a/tests/Android.mk b/tests/Android.mk
index 7acc7be..0edf0c9 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -4,7 +4,7 @@
 # We only want this apk build for tests.
 LOCAL_MODULE_TAGS := tests
 
-LOCAL_STATIC_JAVA_LIBRARIES := mockito-target
+LOCAL_STATIC_JAVA_LIBRARIES := mockito-target legacy-android-test
 
 LOCAL_JAVA_LIBRARIES := android.test.runner