Bug 1411688 - Part 0: Make --with-gradle handle single-locale repack ABIs. r=snorp

This agrees with
http://searchfox.org/mozilla-central/rev/423b2522c48e1d654e30ffc337164d677f934ec3/mobile/android/base/generate_build_config.py#95.
It should really come from the underlying binaries for repacks, but
right now we only repack ARM builds, so this will do.

MozReview-Commit-ID: 3UvrJDV1l9a

--HG--
extra : rebase_source : e57b49e32c80906bdb513850c370d64e5a140978

mobile/android/geckoview/build.gradle

@@ -55,7 +55,8 @@ android {
         // TODO: ensure these fields always agree with mobile/android/geckoview/BuildConfig.java.in,
         // either by diffing the processed files or by generating the output from a single source.
         buildConfigField 'String', "GRE_MILESTONE", "\"${mozconfig.substs.GRE_MILESTONE}\""
-        buildConfigField 'String', "MOZ_APP_ABI", "\"${mozconfig.substs.TARGET_XPCOM_ABI}\"";
+        // This should really come from the included binaries, but that's not easy.
+        buildConfigField 'String', "MOZ_APP_ABI", mozconfig.substs['COMPILE_ENVIRONMENT'] ? "\"${ mozconfig.substs.TARGET_XPCOM_ABI}\"" : '"arm-eabi-gcc3"';
         buildConfigField 'String', "MOZ_APP_BASENAME", "\"${mozconfig.substs.MOZ_APP_BASENAME}\"";
 
         // For the benefit of future archaeologists: