- The _adb_download function doesn't need a package_name argument. This broke _adb_process_file and unnecessarily clutters function calls. Also, the function may be used to download other files or folders too. Generating a random filename seems like the best solution to me since it is less likely to get a duplicate filename and thus to replace an existing file.
- The path /sdcard/Download doesn't necessarily exist. Using /sdcard seems more reliable.
"which su" will return the path of the su binary, or it will return nothing.
The python boolean of a string with something in it (such as the path of the su binary), will be True.
An empty string (where there is no su binary) will be False.
