[fenix] For https://github.com/mozilla-mobile/fenix/issues/18453 - Show SUMO for default browser deeplink on Android <N

Lower Android versions don't offer the possibility of opening system settings
at a specific preference. In this cases we already shown a sumo article
detailing the manual steps each user is expected to perform to change the
system set default browser.

app/src/main/java/org/mozilla/fenix/home/intent/DeepLinkIntentProcessor.kt

@@ -21,6 +21,8 @@ import org.mozilla.fenix.HomeActivity
 import org.mozilla.fenix.browser.browsingmode.BrowsingMode
 import org.mozilla.fenix.components.SearchWidgetCreator
 import org.mozilla.fenix.ext.alreadyOnDestination
+import org.mozilla.fenix.home.intent.DeepLinkIntentProcessor.DeepLinkVerifier
+import org.mozilla.fenix.settings.SupportUtils
 
 /**
  * Deep links in the form of `fenix://host` open different parts of the app.
@@ -93,6 +95,16 @@ class DeepLinkIntentProcessor(
                     settingsIntent.putExtra(SETTINGS_SHOW_FRAGMENT_ARGS,
                         bundleOf(SETTINGS_SELECT_OPTION_KEY to DEFAULT_BROWSER_APP_OPTION))
                     activity.startActivity(settingsIntent)
+                } else {
+                    activity.openToBrowserAndLoad(
+                        searchTermOrURL = SupportUtils.getSumoURLForTopic(
+                            activity,
+                            SupportUtils.SumoTopic.SET_AS_DEFAULT_BROWSER
+                        ),
+                        newTab = true,
+                        from = BrowserDirection.FromGlobal,
+                        flags = EngineSession.LoadUrlFlags.external()
+                    )
                 }
             }
             "open" -> {

app/src/test/java/org/mozilla/fenix/home/intent/DeepLinkIntentProcessorTest.kt

@@ -6,6 +6,9 @@ package org.mozilla.fenix.home.intent
 
 import android.content.Intent
 import android.net.Uri
+import android.os.Build.VERSION_CODES.M
+import android.os.Build.VERSION_CODES.N
+import android.os.Build.VERSION_CODES.P
 import androidx.core.net.toUri
 import androidx.navigation.NavController
 import io.mockk.Called
@@ -27,6 +30,8 @@ import org.mozilla.fenix.NavGraphDirections
 import org.mozilla.fenix.browser.browsingmode.BrowsingMode
 import org.mozilla.fenix.components.SearchWidgetCreator
 import org.mozilla.fenix.helpers.FenixRobolectricTestRunner
+import org.mozilla.fenix.settings.SupportUtils
+import org.robolectric.annotation.Config
 
 @RunWith(FenixRobolectricTestRunner::class)
 class DeepLinkIntentProcessorTest {
@@ -244,9 +249,31 @@ class DeepLinkIntentProcessorTest {
     }
 
     @Test
-    fun `process make_default_browser deep link`() {
+    @Config(minSdk = N, maxSdk = P)
+    fun `process make_default_browser deep link for above API 23`() {
         assertTrue(processor.process(testIntent("make_default_browser"), navController, out))
 
+        verify { activity.startActivity(any()) }
+        verify { navController wasNot Called }
+        verify { out wasNot Called }
+    }
+
+    @Test
+    @Config(maxSdk = M)
+    fun `process make_default_browser deep link for API 23 and below`() {
+        assertTrue(processor.process(testIntent("make_default_browser"), navController, out))
+
+        verify {
+            activity.openToBrowserAndLoad(
+                searchTermOrURL = SupportUtils.getSumoURLForTopic(
+                    activity,
+                    SupportUtils.SumoTopic.SET_AS_DEFAULT_BROWSER
+                ),
+                newTab = true,
+                from = BrowserDirection.FromGlobal,
+                flags = EngineSession.LoadUrlFlags.external()
+            )
+        }
         verify { navController wasNot Called }
         verify { out wasNot Called }
     }

docs/mma.md

@@ -357,7 +357,7 @@ Here is the list of current deep links available, which can be found here in the
   </tr>
   <tr>
     <td>`fenix://make_default_browser`</td>
-    <td>Opens to the Android default apps settings screen. **Only works on Android API >=24**</td>
+    <td>Opens to the Android default apps settings screen. If Android API <= 23 opens tab to support page defined in SupportUtils.SumoTopic.SET_AS_DEFAULT_BROWSER</td>
   </tr>
   <tr>
     <td>`fenix://settings_notifications`</td>