[key-manager] set frame counter on SubMac on a counter reset (#7034)

This commit changes `KeyManager` to use `SetAllMacFrameCounter(0)` to
reset the frame counter(s). This would then ensure that the new
counter value is also set on `SubMac` and radio platform layer
(which can handle the 15.4 frame counter assignments). This addresses
an issue where on Key Sequence update the frame counter values on
`SubMac` and radio platform can remain unchanged.

src/core/thread/key_manager.cpp

@@ -388,7 +388,7 @@ void KeyManager::SetCurrentKeySequence(uint32_t aKeySequence)
     mKeySequence = aKeySequence;
     UpdateKeyMaterial();
 
-    mMacFrameCounters.Reset();
+    SetAllMacFrameCounters(0);
     mMleFrameCounter = 0;
 
     Get<Notifier>().Signal(kEventThreadKeySeqCounterChanged);