DO NOT MERGE: Fix deadlock in AcitivityManagerService.

Don't hold mPidsSelfLocked lock when calling
cleanUpApplicationRecordLocked.

Bug: 31463143
Change-Id: I1fddd06f5e35b67fea041741f5746c57a39208ba
(cherry picked from commit dce4be6)

Author: Sudheer Shanka

services/java/com/android/server/am/ActivityManagerService.java

@@ -2818,16 +2818,19 @@ private final void startProcessLocked(ProcessRecord app,
             app.setPid(startResult.pid);
             app.usingWrapper = startResult.usingWrapper;
             app.removed = false;
+            ProcessRecord oldApp;
+            synchronized (mPidsSelfLocked) {
+                oldApp = mPidsSelfLocked.get(startResult.pid);
+            }
+            // If there is already an app occupying that pid that hasn't been cleaned up
+            if (oldApp != null && !app.isolated) {
+                // Clean up anything relating to this pid first
+                Slog.w(TAG, "Reusing pid " + startResult.pid
+                        + " while app is still mapped to it");
+                cleanUpApplicationRecordLocked(oldApp, false, false, -1,
+                        true /*replacingPid*/);
+            }
             synchronized (mPidsSelfLocked) {
-                ProcessRecord oldApp;
-                // If there is already an app occupying that pid that hasn't been cleaned up
-                if ((oldApp = mPidsSelfLocked.get(startResult.pid)) != null && !app.isolated) {
-                    // Clean up anything relating to this pid first
-                    Slog.w(TAG, "Reusing pid " + startResult.pid
-                            + " while app is still mapped to it");
-                    cleanUpApplicationRecordLocked(oldApp, false, false, -1,
-                            true /*replacingPid*/);
-                }
                 this.mPidsSelfLocked.put(startResult.pid, app);
                 Message msg = mHandler.obtainMessage(PROC_START_TIMEOUT_MSG);
                 msg.obj = app;