Update the getIccId docs to reflect access requirements

In Android 10 access to device identifiers was limited to apps with
the READ_PRIVILEGED_PHONE_STATE permission, carrier privileges, the
READ_DEVICE_IDENTIFIERS appop set to allow, or those that pass a
device / profile owner check. TelephonyManager#getSimSerialNumber
was guarded behind these new access requirements, but the same value
is still accessible via SubscriptionInfo#getIccId. This change
updates the documentation to reflect that the getIccId will no
longer be accessible if the caller does not meet the new access
requirements.

Bug: 131909991
Test: Builds
Change-Id: I03072c65e1c7101538a7a20541d2ac59a2d213e3