Use prctl(PR_CAPBSET_READ) to get the last valid cap on Android.

Not all Android processes will have access to '/proc/sys/kernel/cap_last_cap',
so use prctl() to get the last valid cap on Android.

Bug: 26217031
Change-Id: I7dffc8facca30a2e32c5c310c383e82a07b0519e
2 files changed