Android: add note QPermission under private permission APIs

Link to the newer permission API and note that the private
API can still be used for permission types not covered by
QPermission.

Fixes: QTBUG-130372
Change-Id: I093edd72bc50372eba3b06105087ccd4884b0bac
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Nicholas Bennett <nicholas.bennett@qt.io>
(cherry picked from commit d2a8a0d)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/corelib/platform/android/qandroidextras.cpp

@@ -1160,6 +1160,10 @@ requestPermissionsInternal(const QStringList &permissions)
     Requests the \a permission and returns a QFuture representing the
     result of the request.
 
+    \note QPermission is the recommended API to use for requesting permissions.
+        If QPermission doesn't cover an Android permission you want to request,
+        this preliminary API can still used instead.
+
     \since 6.2
     \sa checkPermission()
 */
@@ -1183,6 +1187,10 @@ QtAndroidPrivate::requestPermissions(const QStringList &permissions)
     Checks whether this process has the named \a permission and returns a QFuture
     representing the result of the check.
 
+    \note QPermission is the recommended API to use for requesting permissions.
+        If QPermission doesn't cover an Android permission you want to request,
+        this preliminary API can still used instead.
+
     \since 6.2
     \sa requestPermission()
 */