Add attr for customizing progress bar corner radius.

Adds progressBarCornerRadius, a private attr that allows tweaking
the corner radius for progress bars and seek bars.

Also adds default values for Material and DeviceDefault themes
as well as a config_progressBarCornerRadius value for OEM
overlaying.

Updates the backgrounds for SeekBar and determinate ProgressBars
to use the new attr.

Bug: 69314526
Test: ag/3659018
Change-Id: Ifb16472da8829c484beb7d034b019ba9545696be