Delay loading of the getRune method ID to the first GoNativeActivity is created. That way, importing golang.org/x/mobile/app will not crash, even for gomobile bind programs that don't include (or use) GoNativeActivity. Fixes golang/go#24490 Change-Id: I4bf90e067700451f7c026e53165b6614366d7a94 Reviewed-on: https://go-review.googlesource.com/104395 Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>