Migrate to DeviceConfig in TextClassifier

ConfigParser is introduced to read the flags from DeviceConfig.
If the flag is missing, fallback to Settings.

Also, adds a new setting key: TEXT_CLASSIFIER_ACTION_MODEL_PARAMS

Test: atest frameworks/base/core/tests/coretests/src/android/view/textclassifier/
Test: adb shell cmd device_config put textclassifier system_textclassifier_enabled  false
      adb shell dumpsys textclassification, observed that the flag is updated.

BUG: 123389900
Change-Id: Icbd26ec7ed223e40b60696d12327cb123b96c4fd