Relax TM.isModemEnabledForSlot with READ_BASIC_PHONE_STATE permission

This change relaxes the permission for API
TelephonyManager.isModemEnabledForSlot, allowing apps with
READ_BASIC_PHONE_STATE to check if modem is enabled for a SIM slot.

Whether modem is enabled for a SIM slot is basic information that
doesn't always need READ_PHONE_STATE or carrier privileges. The relaxed
permission makes the API more useful without leaking sensitive info.

Bug: 401006757
Test: atest CtsTelephony2TestCases CtsTelephonyTestCases
Flag: com.android.internal.telephony.flags.macro_based_opportunistic_networks
Change-Id: Ic163889fcf149e926a85ffba88b7d83069ac532d