Add isMatchRuleMobile back

There's a user still call this method which causes the app
crash and it might be the app was built against hidden API.
The bug was observed after updating the mainline module so
adding this method back to the module to avoid apps crash
due to the method is not found in NetworkTemplate.

Bug: 269178029
Test: build
Change-Id: I06dc694b1ce060488135f5d34138f14abd50ad32
1 file changed