Update hearing device dialog UI to match figma

1. Change the background of the related tool from outlined shape to
   colored background
2. Limit the total number of related tools to 3 and ensure the layout
   will align left and right boundary as same as the above UI elements
   (device items, preset control)

Flag: EXEMPT bugfix
Test: manually check the UI, result attached in bug
Test: atest HearingDevicesDialogDelegateTest
Test: atest HearingDevicesToolItemParserTest
Bug: 372185688
Change-Id: Ic754581d7c0bca9af14192fd74f251e0805d1e22