Fix default permission granting for system TextClassifier.

The original code calls TCS.getServiceComponentName to get the package
name of the configured system TextClassifier, which does not work before
user logs in. This fixes the problem by using the package name from the
configuration directly.

Test: Manually tested to confirm permissions were granted. Permission
section of the app info are gray.

Bug: 74779259

Change-Id: I6bff7119e174c0e0b17d9736d69075f6df2bc882