Fix translation animation flash for the same translation

The system received the same multiple translation responses in a very
short time. We use a isShowingTranslation flag to determine if the
duplicated responses to call onShowTranslation. However the
isShowingTransation flag is set in a post runnable, this may cause the
system  allow the duplicate responses can call onShowTranslation
because the isShowingTransaltion isn't set true yet.

Use multiple flags isShowingTranslation and a new isRunningAnimation
to check if the same translation response should skip to call
onShowTranslation.

Bug: 207457172
Test: manual
Test: atest CtsTranslationTestCases
Change-Id: I7003b7f49fc0a8ce2e909228bcb89acedee6d3d0