Open external links in same activity (commons-app#3395)

It's common for users to expect that re-opening the app would
allow them to "continue where they left off". This also applies
for the case where they leave the app after opening an
external link. It's natural for them to expect that they would
see the webpage they left open when they re-open the app. This
doesn't happen for our app as we open custom tabs in a separate
activity. As a consequence, this makes the experience
un-intuitive.

Fix this by opening custom tabs in the same activity.

Fixes: commons-app#2944

Co-authored-by: Adam Jones <jones_adam@rocketmail.com>

Author: kaartic-sn-20010

app/src/main/java/fr/free/nrw/commons/Utils.java

@@ -145,7 +145,7 @@ public static void handleWebUrl(Context context, Uri url) {
         builder.setExitAnimations(context, android.R.anim.slide_in_left, android.R.anim.slide_out_right);
         CustomTabsIntent customTabsIntent = builder.build();
         // Clear previous browser tasks, so that back/exit buttons work as intended.
-        customTabsIntent.intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
+        customTabsIntent.intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
         customTabsIntent.launchUrl(context, url);
     }