Ignore mismatched hint for button nav

Ignore the mismatched source rect hint if it does not match the reported
aspect ratio for button navigation mode. This is a follow of ag/27829115

Flag: NONE bug fix
Video: http://recall/-/aaaaaabFQoRHlzixHdtY/dOJSECREoYRqafme1TKU15
Bug: 338616637
Bug: 339346128
Test: Enter PiP from split-screen in button navigation mode
Test: Verify the regular enter PiP CUJs in button navigation mode
Change-Id: I4be6007311a14e22bc1e12e81f9fa30438f8bbb7