Switch android.test and junit classes to use UnsupportedAppUsage

The UnsupportedAppUsage annotations could not be added directly to the
java files in src/ as they have to be built against the current api
which does not include the annotation. Instead this uses the same
technique as used for libcore/ojluni files and adds the annotations to
stub files (in hiddenapi/src) which are built as part of the
android.test.base-hiddenapi target. That target is added to a special
whitelist in build/soong/java/config/config.go which causes the
hiddenapi information to be extracted from the target.

Also, updates the preupload check to prevent anymore entries being
added to the config/hiddenapi-greylist.txt for android.test or junit
classes.

Bug: 73711752
Test: m cts-hiddenapi_flags-csv and check that it contained the
        correct entries even though they had been removed from
	config/hiddenapi-greylist.txt
Change-Id: Ifaf15d2751f54cb03f8402b866a0ee4da7acc4d2
diff --git a/tools/hiddenapi/exclude.sh b/tools/hiddenapi/exclude.sh
index 4ffcf68..18c4054 100755
--- a/tools/hiddenapi/exclude.sh
+++ b/tools/hiddenapi/exclude.sh
@@ -9,6 +9,7 @@
 LIBCORE_PACKAGES="\
   android.icu \
   android.system \
+  android.test \
   com.android.bouncycastle \
   com.android.conscrypt \
   com.android.i18n.phonenumbers \
@@ -17,6 +18,7 @@
   dalvik \
   java \
   javax \
+  junit \
   libcore \
   org.apache.harmony \
   org.json \