Add click event to pack theme option.

Build the infra for the click event for the pack theme option. Currently
the navigation event is fake data and written into WPPG. The data will
be replaced after the gRPC pipeline is ready.

Bug: 398982575
Flag: EXEMPT refactor
Test: Tested by building and installing picker on local, checking if the
entry shown as expected.

Change-Id: I2d696626319762df2a039dc98a2d90b267840308