Make sure my_src_jar is set up properly for host prebuilt jar

Make sure my_src_jar is set up properly for host prebuilt jar when we
need to generate host .jack for host dalvik java libraries.

(cherry picked from commit 86e74b96fcc46d6d6c3758b13cca755c12e7de8a)

Change-Id: I79393bc416fafb6d9cd28b12070a58ae5731587d
1 file changed