Increase the debounce 4 sec In the low light environment, the lux value varies and cause the brightness switch frequently. Increase the debounce time 4 seconds to recover it. Bug: 161658240 Test: full build and check the brightness behavior Change-Id: I3dd1791e91e5dc0eaf484ff5e0b20eeb0164400f (cherry picked from commit be18a6e5d16cd32e73368d2090d45f64a68719a8)