Do not reuse the same ProcessRecord if it's not fully gone yet

When force-stopping apps, it's eligible for restart, and during
that we might be reusing the old ProcessRecord before that process
is really gone. Now don't reuse that.

And also, remove the ProcessRecord from the LRU list when we know
it's really gone.

Bug: 286299952
Test: Manual - Clear app data and make sure it could restart correctly.
Change-Id: I2c71c64b962cb9b4ae15881add50c35fd9e4a7af