NativeTombstoneManager: fix tombstone parsing.

For unclear reasons, this was silently succeeding on AOSP, and throwing
a ProtoParseException on internal.

Bug: http://b/159164105
Test: `adb shell crasher` on sc-vf-dev, sc-dev
Change-Id: I605e9db49e344bd57a4e33d32808ca2b5b6f4231
1 file changed