Force libphonenumber to continue to use v51 (1.7) .class files

The default is changing to v52 (1.8).

The build for this package uses jarjar to repackage .class files.

The version of jarjar in the Android tree does not currently
support v52 .class files.

Bug: 26753820
Change-Id: I3d133036b762ee1ebc7f0891441138ee898e0a79
1 file changed