VmTerminalApp: Remove Toast for external storage

Files apps don't show Toast nor Snackbar for missing permission.
Instead, they either indefinitely re-launches the Settings activity
without reason, or show extra dialog about missing permission.

For initial version, we'll take the most simplest option.

Test: Manually
Bug: 375542145
Change-Id: I4854d1a3393fd8db7d06f5bd5c38530f51a50886
diff --git a/android/TerminalApp/java/com/android/virtualization/terminal/MainActivity.java b/android/TerminalApp/java/com/android/virtualization/terminal/MainActivity.java
index ebf6154..fdf1f3b 100644
--- a/android/TerminalApp/java/com/android/virtualization/terminal/MainActivity.java
+++ b/android/TerminalApp/java/com/android/virtualization/terminal/MainActivity.java
@@ -88,7 +88,7 @@
     private AccessibilityManager mAccessibilityManager;
     private ConditionVariable mBootCompleted = new ConditionVariable();
     private static final int POST_NOTIFICATIONS_PERMISSION_REQUEST_CODE = 101;
-    private ActivityResultLauncher<Intent> manageExternalStorageActivityResultLauncher;
+    private ActivityResultLauncher<Intent> mManageExternalStorageActivityResultLauncher;
     private static int diskSizeStep;
 
     @Override
@@ -122,27 +122,17 @@
         readClientCertificate();
         connectToTerminalService();
 
-        manageExternalStorageActivityResultLauncher =
+        mManageExternalStorageActivityResultLauncher =
                 registerForActivityResult(
                         new ActivityResultContracts.StartActivityForResult(),
                         (ActivityResult result) -> {
-                            if (Environment.isExternalStorageManager()) {
-                                Toast.makeText(this, "Storage permission set!", Toast.LENGTH_SHORT)
-                                        .show();
-                            } else {
-                                Toast.makeText(
-                                                this,
-                                                "Storage permission not set",
-                                                Toast.LENGTH_SHORT)
-                                        .show();
-                            }
                             startVm();
                         });
 
         // if installer is launched, it will be handled in onActivityResult
         if (!launchInstaller) {
             if (!Environment.isExternalStorageManager()) {
-                requestStoragePermissions(this, manageExternalStorageActivityResultLauncher);
+                requestStoragePermissions(this, mManageExternalStorageActivityResultLauncher);
             } else {
                 startVm();
             }
@@ -435,7 +425,7 @@
                 finish();
             }
             if (!Environment.isExternalStorageManager()) {
-                requestStoragePermissions(this, manageExternalStorageActivityResultLauncher);
+                requestStoragePermissions(this, mManageExternalStorageActivityResultLauncher);
             } else {
                 startVm();
             }