Add test for setTitleMaxLines in SelectorWithWidgetPreference

Adds a unit test to verify the behavior of the `setTitleMaxLines` method.

The test ensures that calling `setTitleMaxLines` updates the underlying value and that the change is reflected in the title TextView's `maxLines` property after the view is rebound.

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Original Change: ag/35118513
Bug: 431235865
Flag: TEST_ONLY

Test: The generated test has been validated via ABTD - http://go/forrest-run/L80600030016790095

Change-Id: I8dc1d659c0a9a4025ce66a1827c21bfd15ede4f7