Do not thrown on error persisting runtime permissions

bug:20752986

Change-Id: I49d7e30afd49d3dcb1bcffd2fd48e9460ed5147f
diff --git a/services/core/java/com/android/server/pm/Settings.java b/services/core/java/com/android/server/pm/Settings.java
index 286bbfe..6415343 100644
--- a/services/core/java/com/android/server/pm/Settings.java
+++ b/services/core/java/com/android/server/pm/Settings.java
@@ -4339,8 +4339,6 @@
                 Slog.wtf(PackageManagerService.TAG,
                         "Failed to write settings, restoring backup", t);
                 destination.failWrite(out);
-                throw new IllegalStateException("Failed to write runtime permissions,"
-                        + " restoring backup", t);
             } finally {
                 IoUtils.closeQuietly(out);
             }