Add an options to change process priority for runtime optimization

### Please check before submitting an issue

- [x] I am using the latest version of App Manager
- [x] I have searched the issues and haven't found anything relevant
- [x] I have read the docs

### Describe a description of the new feature

When using the runtime optimization, the Dex2Oat process are using a priority of 30? (see the attached image, use top in shell also show that number), which makes sometime the process just stuck at some absolutely random part, or even crash App Manager in the process.

### Describe the solution you'd like

An options/box to change the process priority of the runtime optimization to the lowest possible in the working mode (ie, 0 on ADB and -20 on Root)

### Describe alternatives you've considered

I knows that there are nice and renice command to change the process priority, and you can change the priority to 0 on non-root and -20 on root, so I have tried to change parent and child process priority, change parents do absolutely nothing, the child process is just changing way too fast to have a realistic way to do that by hands, through when the process stuck that tricks is good enough to let the process continue

### Additional context