[content-capture] ensure memory-safe charsequences

When parceling CharSequences, we need to both remove NoCopySpans and
trim to max parcelable size. Fixing a couple of places that only do one
of these operations.

Bug: 239080094

Test: CtsContentCaptureServiceTestCases, FrameworkCoreTests

Change-Id: If6a52a8c9804d06d95b39ceff52c4db076e9b49c