Updated privacy settings to launch custom content capture settings when available.

Test: manual verification
Test: atest EnableContentCapturePreferenceControllerTest \
      CtsContentTestCases:android.content.cts.AvailableIntentsTest#testRequestEnableContentCaptureIntent
Test: adb shell am start-activity -a android.settings.REQUEST_ENABLE_CONTENT_CAPTURE

Fixes: 119264902

Change-Id: I2a030c31d966d40feb6ba449e4bbc9ef8cf0565b