Fix Incognito mode crash in AOSP browser

The menu of incognito is not supported in KK release, delete it.

Change-Id: I461b3133ec49fa067e6730ac8d15feaa9e57a92b
Signed-off-by: bxu10x <binx.xu@intel.com>
Merge "Fix Incognito mode crash in AOSP browser"
auto-merger: merge in from aosp/master