Dont select automatic strategy when stylus is in use

To stop the brightness from changing when stylus is being used, we will
not select the automatic brightness strategy. This way, the selector
will falkback to the next valid strategy(FallbackBrightnessStrategy)
which will select the current brightness

Bug: 352411468
Test: atest com.android.server.display
Flag: com.android.server.display.feature.flags.block_autobrightness_changes_on_stylus_usage
Change-Id: I3014ea0b1e6b71378a1cdfd402b4b37df70f5a20