Don't export activities that don't need to be opened by other apps

app/src/full/AndroidManifest.xml

@@ -38,6 +38,7 @@
         <activity
             android:name=".ui.ipfs.IpfsGatewaySettingsActivity"
             android:configChanges="layoutDirection|locale"
+            android:exported="false"
             android:label="@string/ipfsgw_title"
             android:launchMode="singleTask" />
     </application>

app/src/main/AndroidManifest.xml

@@ -104,12 +104,14 @@
         <activity
             android:name="org.fdroid.ui.crash.CrashActivity"
             android:excludeFromRecents="true"
+            android:exported="false"
             android:finishOnTaskLaunch="true"
             android:launchMode="singleInstance"
             android:process=":acra"
             android:windowSoftInputMode="adjustResize" />
         <activity
             android:name="com.journeyapps.barcodescanner.CaptureActivity"
+            android:exported="false"
             android:screenOrientation="fullSensor"
             tools:ignore="DiscouragedApi"
             tools:replace="screenOrientation" />