Updated comment for enableModem().

Test: build
Bug: 124771128
Change-Id: I9ddd679daa9b806b8c8677b9d4ef54dacb40d242
diff --git a/radio/1.3/IRadio.hal b/radio/1.3/IRadio.hal
index 95cf615..922b35d 100644
--- a/radio/1.3/IRadio.hal
+++ b/radio/1.3/IRadio.hal
@@ -49,8 +49,13 @@
             vec<RadioAccessSpecifier> specifiers);
 
    /**
-    * Toggle logical modem on and off. The difference with setRadioPower is,
-    * setRadioPower affects all logical modems while this controls just one.
+    * Toggle logical modem on/off. This is similar to @1.0::IRadio.setRadioPower(), however that
+    * does not enforce that radio power is toggled only for the corresponding radio and certain
+    * vendor implementations do it for all radios. This new API should affect only the modem for
+    * which it is called. A modem stack must be on/active only when both setRadioPower() and
+    * enableModem() are set to on for it.
+    *
+    * SIM must be read if available even if modem is off/inactive.
     *
     * @param serial Serial number of request.
     * @param on True to turn on the logical modem, otherwise turn it off.