The constructor of SystemCleaner shouldn't be public

The API was accidentally added in https://r.android.com/1950582.
Luckily, the API level hasn't changed, and should be safe to be removed.

Bug: 217689064
Test: m droid
Change-Id: I46fbbf5614b3fd260cb8b20b841d7bf26fca59e8
2 files changed