hevcenc: Correctly update second best mv candidate in hme coarse layers

Test: poc in the bug report
Test: atest CtsMediaV2TestCases:CodecEncoderTest
Test: atest VtsHalMediaC2V1_0TargetVideoEncTest

Bug: 207502397

Change-Id: I0bc050ca4804b724bc226d6f00f798696d1b5c65
(cherry picked from commit 057f2f3aae4f60765c14deafe38ad75e93e85d34)
Merged-In: I0bc050ca4804b724bc226d6f00f798696d1b5c65
2 files changed