mkbootimg: chmod +x mkbootimg.py am: 1684c1ff9c

Original change: https://android-review.googlesource.com/c/platform/system/tools/mkbootimg/+/1601573

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I1af64d3c6265780b1cb416c3ab50bdbbdf65e65a
diff --git a/mkbootimg.py b/mkbootimg.py
old mode 100644
new mode 100755