Catch ActivityNotFoundException when choosing files.

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationActivity.java

@@ -1,6 +1,7 @@
 package org.briarproject.briar.android.conversation;
 
 import android.annotation.SuppressLint;
+import android.content.ActivityNotFoundException;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.graphics.drawable.Drawable;
@@ -121,6 +122,7 @@ import uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt;
 
 import static android.os.Build.VERSION.SDK_INT;
 import static android.view.Gravity.RIGHT;
+import static android.widget.Toast.LENGTH_LONG;
 import static android.widget.Toast.LENGTH_SHORT;
 import static androidx.core.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
 import static androidx.lifecycle.Lifecycle.State.STARTED;
@@ -774,7 +776,12 @@ public class ConversationActivity extends BriarActivity
 
 	@Override
 	public void onAttachImageClicked() {
-		launcher.launch("image/*");
+		try {
+			launcher.launch("image/*");
+		} catch (ActivityNotFoundException e) {
+			Toast.makeText(this, R.string.error_start_activity,
+					LENGTH_LONG).show();
+		}
 	}
 
 	private void onImagesChosen(@Nullable List<Uri> uris) {

briar-android/src/main/java/org/briarproject/briar/android/removabledrive/ReceiveFragment.java

@@ -1,5 +1,6 @@
 package org.briarproject.briar.android.removabledrive;
 
+import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.net.Uri;
 import android.os.Bundle;
@@ -68,9 +69,14 @@ public class ReceiveFragment extends Fragment {
 		scrollView = (ScrollView) v;
 		progressBar = v.findViewById(R.id.progressBar);
 		button = v.findViewById(R.id.fileButton);
-		button.setOnClickListener(view ->
+		button.setOnClickListener(view -> {
-				launcher.launch("*/*")
+			try {
-		);
+				launcher.launch("*/*");
+			} catch (ActivityNotFoundException e) {
+				Toast.makeText(requireContext(),
+						R.string.error_start_activity, LENGTH_LONG).show();
+			}
+		});
 		viewModel.getOldTaskResumedEvent()
 				.observeEvent(getViewLifecycleOwner(), this::onOldTaskResumed);
 		viewModel.getState()

briar-android/src/main/java/org/briarproject/briar/android/removabledrive/SendFragment.java

@@ -1,5 +1,6 @@
 package org.briarproject.briar.android.removabledrive;
 
+import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.net.Uri;
 import android.os.Bundle;
@@ -73,9 +74,14 @@ public class SendFragment extends Fragment {
 		introTextView = v.findViewById(R.id.introTextView);
 		progressBar = v.findViewById(R.id.progressBar);
 		button = v.findViewById(R.id.fileButton);
-		button.setOnClickListener(view ->
+		button.setOnClickListener(view -> {
-				launcher.launch(viewModel.getFileName())
+			try {
-		);
+				launcher.launch(viewModel.getFileName());
+			} catch (ActivityNotFoundException e) {
+				Toast.makeText(requireContext(),
+						R.string.error_start_activity, LENGTH_LONG).show();
+			}
+		});
 
 		viewModel.getOldTaskResumedEvent()
 				.observeEvent(getViewLifecycleOwner(), this::onOldTaskResumed);

briar-android/src/main/java/org/briarproject/briar/android/settings/SettingsFragment.java

@@ -1,10 +1,12 @@
 package org.briarproject.briar.android.settings;
 
+import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
 import android.view.View;
+import android.widget.Toast;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
@@ -23,6 +25,7 @@ import androidx.preference.Preference;
 import androidx.preference.PreferenceFragmentCompat;
 import androidx.preference.PreferenceGroup;
 
+import static android.widget.Toast.LENGTH_LONG;
 import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.AppModule.getAndroidComponent;
 import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
@@ -65,7 +68,12 @@ public class SettingsFragment extends PreferenceFragmentCompat {
 		prefAvatar = requireNonNull(findPreference(PREF_KEY_AVATAR));
 		if (viewModel.shouldEnableProfilePictures()) {
 			prefAvatar.setOnPreferenceClickListener(preference -> {
-				launcher.launch("image/*");
+				try {
+					launcher.launch("image/*");
+				} catch (ActivityNotFoundException e) {
+					Toast.makeText(requireContext(),
+							R.string.error_start_activity, LENGTH_LONG).show();
+				}
 				return true;
 			});
 		} else {