Update setNullCipherAndIntegrityEnabled doc

Specify behavior for 2G vs 3G and above.

Bug: 237529943
Test: n/a
Change-Id: I79663e074799290b42a42431df4cdedf3bf3830a
diff --git a/radio/aidl/android/hardware/radio/network/IRadioNetwork.aidl b/radio/aidl/android/hardware/radio/network/IRadioNetwork.aidl
index 38772cd..86b6eca 100644
--- a/radio/aidl/android/hardware/radio/network/IRadioNetwork.aidl
+++ b/radio/aidl/android/hardware/radio/network/IRadioNetwork.aidl
@@ -487,15 +487,21 @@
 
     /**
      * Set if null encryption and integrity modes are enabled. If the value of enabled is false
-     * the modem must not allow any network communications with null ciphering or null integrity
-     * modes.
+     * the modem must not allow any network communications with null ciphering (for both signalling
+     * and user data) or null integrity (for signalling) modes for 3G and above, even if the
+     * network only uses null algorithms. This setting must be respected even if
+     * "cipheringDisabled" (as defined in TS 38.331) is in use by the network.
+     *
+     * For 2G, which does not use integrity protection, the modem must only disallow any network
+     * communications with null ciphering.
      *
      * In the case when enabled is false, integrity protection for user data is optional, but
-     * ciphering for user data is required. In case of an emergency call, the modem must bypass
-     * this setting.
+     * ciphering for user data is required.
+     *
+     * In case of an emergency call, the modem must bypass this setting.
      *
      * Null ciphering and integrity modes include (but are not limited to):
-     * 2G: A5/0
+     * 2G: A5/0 and GEA0
      * 3G: UEA0 and UIA0
      * 4G: EEA0 and EIA0
      * 5G: NEA0 and NIA0