Bug 1395486 followup. Clobber to fix packaging failure for Android builds. r=clobber

For the underlying problem, see bug 1395286.

CLOBBER

@@ -22,4 +22,4 @@
 # changes to stick? As of bug 928195, this shouldn't be necessary! Please
 # don't change CLOBBER for WebIDL changes any more.
 
-Bug 1395286 - Fix packaging error for Android builds, presumably due to bug 1255404 and/or bug 863246.
+Bug 1395486 - Moving files to content-accessible requires a clobber so as not to break Android packaging.