Fix the atest can't start with single test

When the developer want to start single test by using
"atest package:class_name#method_name" but doesn't work.
To replace InstrumentationTest with AndroidJunitTest in Android.bp.

Bug: 129309239
Test: TID="DownloadProviderTests"; \
      PACKAGE_NAME="com.android.providers.downloads"; \
      TEST_CLASS="DownloadProviderFunctionalTest"; \
      TEST_METHOD="testDownloadToCache"; \
      atest "${TID}:${PACKAGE_NAME}.${TEST_CLASS}#${TEST_METHOD}"

Change-Id: If592035777f7cc69a4a2e20aebf77867251774c8
1 file changed