Fix race conditions in removing dying process record

While waiting for the death of a process, if its subsequent process
record is created and killed immediately, we may end up removing
the former process record from the dying process list.

Bug: 201305599
Test: Presubmit
Change-Id: Ib62a3644d927881d7dab577b625460239e54b434

services/core/java/com/android/server/am/ProcessList.java

@@ -5143,7 +5143,8 @@ public final class ProcessList {
         }
 
         Watchdog.getInstance().processDied(app.processName, app.getPid());
-        if (app.getDeathRecipient() == null) {
+        if (app.getDeathRecipient() == null
+                && mDyingProcesses.get(app.processName, app.uid) == app) {
             // If we've done unlinkDeathRecipient before calling into this, remove from dying list.
             mDyingProcesses.remove(app.processName, app.uid);
             app.setDyingPid(0);