Make mkbootimg a py_binary.

Bug: 433545832
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:9cb122497de8a9083495b09b4c470834d8834aaa)
Merged-In: I51cca9384a05aab89898844d99e1697d15f9a383
Change-Id: I51cca9384a05aab89898844d99e1697d15f9a383
1 file changed