DO NOT MERGE: Fix testFormatSameDayTime test for 2020a update [N MR1/N MR2]

Change test assumptions for formating the GMT timezone, which was
changed with a 2020a update.

Bug: 157444326
Test: run cts -m CtsTextTestCases
Change-Id: Ia9915b99a7e2c3d805319b11c66f05b0e0362ceb
1 file changed