Stop showing both the floating toolbar and suggestions

The selection mode without selection (PASTE|SELECT_ALL)
pops up along the suggestion popup if we tap on a word
within 15sec of the most recent cut/copy/textChanged
operation. Fix this by making suggestion popup take
precedence.

Also moved the invalidation of the text changed time
into the handleTextChanged() which fixes the selection
mode starting once after the text has changed.

NOTE: Subsequent clicks on non-suggestion spans will
still trigger the selection mode without selection if
within the defined timeframe.

Bug: 20443325
Change-Id: If2726e2c965e77e82ef7b847cf352d4426205bdc