The account name could be PII or email address that should not be
printed in android logs or dumpsys. In account manager output, call
Account.toSafeString() to replace letters/digits in account name with
character 'x'.
Change-Id: Ic1abd1ecda99a309e8973f13bd3650286bbd59e6
Fix: 111937873
Test: atest AccountTest.java