Delete unencrypted files each time the app is started

vector/src/main/java/im/vector/app/features/home/HomeActivityViewModel.kt

@@ -71,12 +71,18 @@ class HomeActivityViewModel @AssistedInject constructor(
     private var onceTrusted = false
 
     init {
+        cleanupFiles()
         observeInitialSync()
         mayBeInitializeCrossSigning()
         checkSessionPushIsOn()
         observeCrossSigningReset()
     }
 
+    private fun cleanupFiles() {
+        // Mitigation: delete all cached decrypted files each time the application is started.
+        activeSessionHolder.getSafeActiveSession()?.fileService()?.clearDecryptedCache()
+    }
+
     private fun observeCrossSigningReset() {
         val safeActiveSession = activeSessionHolder.getSafeActiveSession() ?: return