Skip checking the app op for step sensors for legacy apps

To maintain backwards compatibility, ensure that apps with target SDK
set to P or lower get access to step count and detect sensors,
regardless of their permission status. After a change was made to the
app ops code in rvc-dev, this check resulted in compatibility breakage
for some apps built with target SDK before Q.

Fixes: 157638722
Test: confirm that a popular step counting app from the Play Store is
      able to receive step count events after the change (where it
      couldn't before)
Change-Id: Idab0ec458221524997f68311f4c6b216c969cb61