Use TextClassicationSession to call smart selection APIs.

We used to use TextClassicationSession to send us logging only (i.e.
onSelectionEvent()). Now we use TCSession to call smart selection APIs
(i.e. suggestSelection and classifyText). This allows the TCS to
obtain the session ID in onSuggestSelection and onClassifyText.

BUG: 149077320

Test: atest TextViewActivityTest
Test: Try a few smart selections and log the sessionID of each TC APIs.

Change-Id: I320249735aa08fb7e8612060955b2aa5496da94b