This allows us to keep the assigned permissions when apps are temporarily
removed due to the SD card being unmounted, and also if you use the
facility to uninstall an app but keep its data.
Also fixes issue #2515189: Potential permission spoofing attack in
Android (external bug 7166)
Change-Id: I2a120ec938552028c989f9e0e890c32773957738
There are three major classes of changes here:
- Avoid writing lines where their values are often empty, false, or some other typical thing.
- Use partial writes to the PrintWriter to avoid creating temporary strings.
- Use StringBuilder where we need to generate real String objects (and where possible cache the result).
