Raise popup show/hide delay to 500ms/300ms, respectively

Per discussion on the bug, the current values of 150ms/100ms cause a
lot of unintended actions.

Bug: 64234
Change-Id: I6fe2d89ad97630ec5c7f47d3e3b9b71d7cfc5d3f
Merge "Raise popup show/hide delay to 500ms/300ms, respectively"