Shows ripple effect for SettingsSpinnerPreference

Before this change, only the spinner inside
SettingsSpinnerPreference is clickable. The preference
itself is not clickable.

After this change, whole preference area is clickable
and it will show dropdown view of the spinnner at
onPreferenceClick.

Bug: 187142293
Test: atest SettingsSpinnerPreferenceTest
      manual visual
      Inserts an USB flash drive and clicks SettingsSpinnerPreference
      in Storage Settings.
Change-Id: Ib4de017e6f5930f7b29c8958f2fe7f7dbe347324