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.

(cherry picked from 6387604f9e672ece85e07c4bcbd7be396867f06f)

Bug: 30188076
Test: make checkbuild
Merged-In: I13e88297731253420e4e5f5291d503f13a39a156
Change-Id: I58446eb8c45d8ac2bcdbc9fa40d1321e811bdd4b