Prune class2greylisttest out of general-tests.

These tests define test_suite as 'general-tests' only but not used in
Test Mapping Suite. Hence, we plan to prune them to reduce size/build
time of general-tests.zip. They are listed as below:
 - class2greylisttest

Bug: 139893779

Test: m general-tests
Change-Id: I1755c5201d944debb45eb02beb921ab5bdcc02ea
diff --git a/tools/class2greylist/test/Android.bp b/tools/class2greylist/test/Android.bp
index ed1fda2..8d5c827 100644
--- a/tools/class2greylist/test/Android.bp
+++ b/tools/class2greylist/test/Android.bp
@@ -25,7 +25,4 @@
         "junit-host",
         "objenesis",
     ],
-
-    // tag this module as a cts test artifact
-    test_suites: ["general-tests"],
 }