C11 has been the platform (and compiler) default for a while now. am: a9963b538c am: e10ea8f194 am: 6a5d255168

Original change: https://android-review.googlesource.com/c/platform/external/mtools/+/2628331

Change-Id: I575c7d333b358f68bbdc5a5f3317a0ad327829e1
Signed-off-by: Automerger Merge Worker <[email protected]>