Android VM lifecycle: prompt EE stop + fix 2nd-launch kick-back

- R5900 _cpuEventTest_Shared: bail out early on VMState::Stopping/Shutdown and
  on IsExecutionInterrupted() so the EE leaves Execute() promptly on stop
  (previously hit the ~5s shutdown timeout).
- native-lib Host::RequestVMShutdown: no-op if already Shutdown. The queued
  task could re-set Stopping after the run loop already reached Shutdown,
  sticking s_state at Stopping so the next Initialize failed 'already running'
  -- kick back to library on the 2nd game boot.

pcsx2/R5900.cpp

@@ -363,6 +363,20 @@ __fi void _cpuEventTest_Shared()
 	eeEventTestIsActive = true;
 	cpuRegs.nextEventCycle = cpuRegs.cycle + eeWaitCycles;
 	cpuRegs.lastEventCycle = cpuRegs.cycle;
+
+	// Android's in-game Exit/Reset can flip the VM to Stopping from another
+	// thread while the EE recompiler is in its generated-code event path. Once
+	// Stopping is visible, do not continue into IOP counters/VU sync; return
+	// immediately so the recompiler's outer recEventTest can fastjmp out of
+	// Cpu->Execute(). Without this, PSX-vsync/IOP work can keep running after
+	// the stop latch and the Java shutdown call times out.
+	const VMState vm_state = VMManager::GetState();
+	if (vm_state == VMState::Stopping || vm_state == VMState::Shutdown)
+	{
+		eeEventTestIsActive = false;
+		return;
+	}
+
 	// ---- INTC / DMAC (CPU-level Exceptions) -----------------
 	// Done first because exceptions raised during event tests need to be postponed a few
 	// cycles (fixes Grandia II [PAL], which does a spin loop on a vsync and expects to
@@ -427,6 +441,17 @@ __fi void _cpuEventTest_Shared()
 			_cpuTestInterrupts();
 	}
 
+#if defined(__ANDROID__)
+	// Android pause/stop requests can be pumped during the counter/vsync work
+	// above. Once that happens, return to the rec/interpreter wrapper immediately
+	// instead of continuing through VU sync and scheduling a fresh event.
+	if (VMManager::Internal::IsExecutionInterrupted())
+	{
+		eeEventTestIsActive = false;
+		return;
+	}
+#endif
+
 	// ---- VU Sync -------------
 	// We're in a EventTest.  All dynarec registers are flushed
 	// so there is no need to freeze registers here.

platforms/android/app/src/main/cpp/native-lib.cpp

@@ -2598,6 +2598,15 @@ void Host::RequestExitBigPicture()
 
 void Host::RequestVMShutdown(bool allow_confirm, bool allow_save_state, bool default_save_state)
 {
+    // This runs as a queued CPU-thread task (Host::RunOnCPUThread from the shutdown
+    // JNI). Since the EE now bails out of Execute() promptly on Stopping, the run
+    // loop can reach its post-Shutdown message pump and process THIS task AFTER
+    // VMManager::Shutdown(false) already drove s_state to Shutdown. Re-setting
+    // Stopping here would leave s_state stuck at Stopping, so the next game's
+    // VMManager::Initialize fails with "already running" (kick-back to library on
+    // the 2nd launch). If we're already shut down, there's nothing left to stop.
+    if (VMManager::GetState() == VMState::Shutdown)
+        return;
     VMManager::SetState(VMState::Stopping);
     if (!s_execute_exit.load(std::memory_order_acquire) && Cpu)
         Cpu->ExitExecution();