This does not break the dependency on the app package's AndroidContext
for loading assets on android. A potential answer for gobind-based
apps: add a SetAndroidContext method to app.Context. But I'll explore
that separately after the long weekend.
Change-Id: I812f899740e288c379eee7900f42d9d53926d4ce
Reviewed-on: https://go-review.googlesource.com/11675
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
