Set different affinity for display activity

Bug: 389524419
Test: run display activity
Change-Id: I170b032e014f708b383949ab6d50ace8069a60e9
diff --git a/android/TerminalApp/AndroidManifest.xml b/android/TerminalApp/AndroidManifest.xml
index c11b1a0..8ed2f79 100644
--- a/android/TerminalApp/AndroidManifest.xml
+++ b/android/TerminalApp/AndroidManifest.xml
@@ -48,6 +48,7 @@
             </intent-filter>
         </activity>
         <activity android:name=".DisplayActivity"
+            android:taskAffinity="com.android.virtualization.terminal.display"
             android:screenOrientation="landscape"
             android:resizeableActivity="false"
             android:theme="@style/FullscreenTheme"