Revert "Revert "Revert "Revert "Switch to source-built GSON.""""

This reverts commit b2e0d45c5bd919a11f5f032171d96abcdd7fb197.

Reason for revert: Re-land again. It looks like the manifest change in aosp/2199915 didn't propagate to the tradefed branch yet when I submitted this change last time.

Change-Id: I84a638bcd4af3bae07c9e5b0ec408215db18314a
diff --git a/Android.bp b/Android.bp
index 1e7beaf..9c5ff92 100644
--- a/Android.bp
+++ b/Android.bp
@@ -667,7 +667,7 @@
     ],
     static_libs: [
         "error_prone_annotations",
-        "gson-prebuilt-jar",
+        "gson",
         "guava-21.0",
         "libprotobuf-java-full",
     ],