It seems like setting the

ImeAction

on TextFields stopped working. I guess it is related to this fix:

Added single line keyboard option to CoreTextField (<https://android-review.googlesource.com/#/q/I72e6d9f84abbf4ff6a9ede5355de4c30d37c3d8c|I72e6d>)

I guess you want to follow this PR: https://android-review.googlesource.com/c/platform/frameworks/support/+/1479049