Change Transparency to Opacity

* In context, this makes more sense. One does not go 100% non-Transparent.
  You become 100% opaque. Due to this, we're switching the string to make
  more sense here.

Change-Id: I4f6542299c8ab94f2d897c872eafc4fe97d0d968
Signed-off-by: AKabhishek <abhishekkaushik.star@gmail.com>

res/values/strings.xml

@@ -632,7 +632,7 @@
     <string name="default_iconpack_title">Default icons</string>
 
     <!-- QuickSettings Panel Transparency -->
-    <string name="qs_panel_alpha_title">Transparency</string>
+    <string name="qs_panel_alpha_title">Opacity</string>
 
 </resources>