Remove outdated @SuppressLint("NewApi") in transition lib

They were intended to be removed together with the refactoring from BuildCompat.isAtLeastQ() to Build.VERSION.SDK_INT >= 29 but was left.

Test: lint succeed
Change-Id: I26418be5ca0d52bd0dfa2b5ef0afef3772cd9b20

• transition/transition/src/main/java/androidx/transition/ImageViewUtils.java[diff]
• transition/transition/src/main/java/androidx/transition/ViewGroupUtils.java[diff]
• transition/transition/src/main/java/androidx/transition/ViewUtils.java[diff]