Use InSameDir helper
Use InSameDir helper

Use Soong's `InSameDir` helper function when calculating paths for
generated implicit sources in `gensrcs_bob` modules. This avoids using
the `ctx.BuildDir()` function, which has been renamed recently, and
therefore allows Bob to build on newer versions of Android.

Change-Id: I278ae82ddd4e5620d69b556d34752c2f7c49b6be
Signed-off-by: Chris Diamand <1f58517798882095082bdee11eba81705511491e@arm.com>

ARM-software/bob-build,ARM-software/bob-build,ARM-software/bob-build,ARM-software/bob-build,ARM-software/bob-build