KeyguardManager set + validate lock API refinement

KeyguardManager#validateLockPasswordComplexity
-> KeyguardManager#isValidLockPasswordComplexity

parameter changes: boolean isPin -> int locktype

Bug: 149298492
Test: TreeHugger
Change-Id: Icc1ab6c3a0eb4637d7e6fb34f95b8a72ced50f98
Signed-off-by: Julius D'souza <jdsouza@google.com>