CAS: Add openSession with no params

Add method to open a session with no arguments.

Bug: 266169861
Test: atest CtsMediaMiscTestCases

Change-Id: I912de02407716c9a5bcd28dabfa8eb8f45aef727
diff --git a/cas/aidl/default/CasImpl.h b/cas/aidl/default/CasImpl.h
index 84a8115..2488a7f 100755
--- a/cas/aidl/default/CasImpl.h
+++ b/cas/aidl/default/CasImpl.h
@@ -53,6 +53,8 @@
 
     virtual ScopedAStatus setPrivateData(const vector<uint8_t>& pvtData) override;
 
+    virtual ScopedAStatus openSessionDefault(vector<uint8_t>* sessionId) override;
+
     virtual ScopedAStatus openSession(SessionIntent intent, ScramblingMode mode,
                                       vector<uint8_t>* sessionId) override;