Rename CaptivePortalLogin for better UX

CaptivePortalLogin is the current app name for the login screen
activity. This is shown in the app recents or the app information
in the Settings but doesn't look good. Some translations have
translated the name but some have not. Rename it for better UX.

Bug: 239883698
Test: m
Change-Id: I21a85793ebea0323c2cb47424166dfe42adc0b49
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 3586fba..bf0241e 100755
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -1,7 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-
-    <string name="app_name">CaptivePortalLogin</string>
+    <!-- When the user connects to a network that has a captive portal (for example the login page
+    of some coffee shop wifi), the system uses an integrated app to show the user the login page.
+    This is the name of this app. It should be translated in each language (not used as-is). -->
+    <string name="app_name">Captive Portal Login</string>
     <string name="action_use_network">Use this network as is</string>
     <string name="action_do_not_use_network">Do not use this network</string>
     <string name="action_bar_label">Sign in to network</string>