Handle reinjection more safely under KernelSU late-load / soft restart

[byemaxx]

I found a stability issue when using the current version under KernelSU late-load (jailbreak) mode, especially after soft restart.

Problem

Multiple surviving daemon instances may still exist after restart, and they can react to the same system_server restart concurrently.

This can lead to:

• duplicated reinjection attempts
• duplicated proxy service re-registration
• duplicated dex2oat wrapper restart
• unstable framework injection state after soft restart

Proposed solution

This patch adds a simple reinjection coordination mechanism:

• a single active reinjection owner
• cross-process reinjection locking
• stale-owner takeover if the recorded owner is no longer alive

The goal is to make reinjection handling more deterministic under KernelSU late-load / soft restart, and avoid multiple daemon instances racing on the same restart event.
This might not be the best solution, but it solved the problem for now in my tests.