1. Keeping state descriptions for the seekbar as an array in the
PreviewSizeSeekBarController when we would like to customize the
state description.
2. Setting the scaled value to be the state description for the font
scaling seekbar when there is a progress change to the seekbar.
Bug: 269212483
Test: manually - attach videos to the bug
Test: make RunSettingsRoboTests ROBOTEST_FILTER=PreviewSizeSeekBarControllerTest
Change-Id: I8e9e3681a0174f454cac871ebf62d785962c7165
d2c53a2085