Refine TC request classes.

Centrialize SystemTextClassifier fields into a class, e.g. userId,
useDefault, callingPackageName. Then all the TextClassifer request
should contain this class object. This helps to scalability if we
want to add new fields.

Bug: 149080832
Test: atest FrameworksCoreTests:android.view.textclassifier
Test: atest FrameworksCoreTests:android.widget.TextViewActivityTest
Test: atest CtsTextClassifierTestCases
Test: Manual. Check the parameters are expected when doing smart
selection, smart linkfy.
Change-Id: I224208adac333e2da7b4213f0905f6fb0abb8b2e

Change-Id: Iaef82c1d6ec8893888258820ac103f1b988eecfa