Add android.test.base/stubs dependency

In preparation for the removal of the non-junit classes in the
android.test.base library from the android.jar this adds a dependency
on android.test.base/stubs to ensure this code will continue to
compile.

The following change descriptions were generated automatically and so
may be a little repetitive. They are provided to give the reviewer
enough information to check the comments match what has actually been
changed and check the reasoning behind the changes.

* tests/functional/applinktests/Android.mk
    Added 'android.test.base.stubs' to LOCAL_JAVA_LIBRARIES because
    AppLinkFunctionalTests's will need them in order to compile once
    its classes are removed from the current SDK on which it currently
    depends.

* tests/functional/downloadapp/Android.mk
    Added 'android.test.base.stubs' to LOCAL_JAVA_LIBRARIES because
    DownloadAppFunctionalTests's will need them in order to compile
    once its classes are removed from the current SDK on which it
    currently depends.

* tests/functional/overviewtests/Android.mk
    Added 'android.test.base.stubs' to LOCAL_JAVA_LIBRARIES because
    OverviewFunctionalTests's will need them in order to compile once
    its classes are removed from the current SDK on which it currently
    depends.

* tests/functional/permission/Android.mk
    Added 'android.test.base.stubs' to LOCAL_JAVA_LIBRARIES because
    PermissionFunctionalTests's will need them in order to compile once
    its classes are removed from the current SDK on which it currently
    depends.

* tests/jank/jankmicrobenchmark/Android.mk
    Added 'android.test.base.stubs' to LOCAL_JAVA_LIBRARIES because
    JankMicroBenchmarkTests's will need them in order to compile once
    its classes are removed from the current SDK on which it currently
    depends.

* tests/jank/sysapp_wear/Android.mk
    Added 'android.test.base.stubs' to LOCAL_JAVA_LIBRARIES because
    SysAppJankTestsWear's will need them in order to compile once its
    classes are removed from the current SDK on which it currently
    depends.

* tests/jank/touch_latency_wear/Android.mk
    Added 'android.test.base.stubs' to LOCAL_JAVA_LIBRARIES because
    TouchLatencyJankTestWear's will need them in order to compile once
    its classes are removed from the current SDK on which it currently
    depends.

* tests/jank/uibench/Android.mk
    Added 'android.test.base.stubs' to LOCAL_JAVA_LIBRARIES because
    UiBenchJankTests's will need them in order to compile once its
    classes are removed from the current SDK on which it currently
    depends.

* tests/jank/uibench_wear/Android.mk
    Added 'android.test.base.stubs' to LOCAL_JAVA_LIBRARIES because
    UiBenchJankTestsWear's will need them in order to compile once its
    classes are removed from the current SDK on which it currently
    depends.

Bug: 30188076
Test: make dist
Change-Id: I8bdd21db153c8caf546076699ba4273fa4a4afd4