Add APIs for available memory on eUICC.

Add new API flag. And add permissions check for:
READ_PHONE_STATE permission and
READ_PHONE_STATE_PRIVILEGED and carrier privilege.

Bug: 312793756
Test: m, atest EuiccServiceTest EuiccConnectorTest EuiccControllerTest EuiccManagerTest
Change-Id: I622ffb45cc3e98ee362b1406db936c7734d99f64