Refactor PinStorage#storePin to avoid dead lock when unlock PIN.

There'll be dead lock if we try to get iccid (acquire UiccController)
after PinStorage lock acquired since another process will try to get
locks in reverse order.

Bug: 200588835
Test: FrameworksTelephonyTests:PinStorageTest
Change-Id: Ib84e75e7d7e72a052d8311535de38a5c985e7d1b