Merge "build: make fs_config_generator.py python2 explicitly" am: bda655ce...

Merge "build: make fs_config_generator.py python2 explicitly" am: bda655ce am: e498803a am: d2d8acb3

Original change: https://android-review.googlesource.com/c/platform/build/+/1478497

Change-Id: I065970fb428c8c5848523d23c807bcd039859efa