Add new error for system errors that are retryable

Some issues require a system error to be raised that
indicates we should retry the process. This adds a new
error and bumps the version of the api for future use.

Test: atest keystore2_test
Bug: 238619180
Change-Id: Iff8fa83f7b223e08de9fa31434e16aa3aa2153f6
diff --git a/keystore2/android.system.keystore2-service.xml b/keystore2/android.system.keystore2-service.xml
index 45f995c..4d8a756 100644
--- a/keystore2/android.system.keystore2-service.xml
+++ b/keystore2/android.system.keystore2-service.xml
@@ -1,7 +1,7 @@
 <manifest version="1.0" type="framework">
     <hal format="aidl">
         <name>android.system.keystore2</name>
-        <version>3</version>
+        <version>4</version>
         <interface>
             <name>IKeystoreService</name>
             <instance>default</instance>