Disable inattentive sleep by default on TVs

Removes the default value of 4 hours for the inattentive sleep timeout
on TVs. Vendors should opt-in to this feature by overriding
`config_attentiveTimeout`.

Bug: 137633812
Test: build
Test: Check attentive timeout in `adb shell dumpsys power`
Change-Id: I09abde67839a893565112f0a041f51f0f75be164