Update the NNAPI OWNERS file

This CL makes the following changes to the NNAPI OWNERS file:
* Removes dgross@ and xusongw@
* Changes butlermichael@ and miaowang@ to be LAST_RESORT_SUGGESTION

Change-Id: Idf7e12cb9b5d61cf5619b1983ae08ce244f8793b
1 file changed