Update bandwidth and time saved text on NTP

Change "Estimated bandwidth saved" to "Bandwidth saved"
Change "Estimated time saved" to "Time saved"

Fix brave/brave-browser#9838

components/resources/brave_components_strings.grd

@@ -150,8 +150,8 @@
       <!-- WebUI newtab resources -->
       <message name="IDS_BRAVE_NEW_TAB_TOTAL_ADS_TRACKERS_BLOCKED" desc="total number of ads and trackers blocked">Trackers &amp; ads blocked</message>
       <message name="IDS_BRAVE_NEW_TAB_TOTAL_HTTPS_UPGRADES" desc="total number of HTTPS upgrades">HTTPS Upgrades</message>
-      <message name="IDS_BRAVE_NEW_TAB_TOTAL_TIME_SAVED" desc="total time saved from blocking ads and trackers">Estimated time saved</message>
-      <message name="IDS_BRAVE_NEW_TAB_ESTIMATED_BANDWIDTH_SAVED" desc="total bandwidth saved from blocking ads and trackers">Estimated bandwidth saved</message>
+      <message name="IDS_BRAVE_NEW_TAB_TOTAL_TIME_SAVED" desc="total time saved from blocking ads and trackers">Time saved</message>
+      <message name="IDS_BRAVE_NEW_TAB_ESTIMATED_BANDWIDTH_SAVED" desc="total bandwidth saved from blocking ads and trackers">Bandwidth saved</message>
       <message name="IDS_BRAVE_NEW_TAB_THUMB_REMOVED" desc="Shown when a thumbnail is removed from the new tab page">Top site removed.</message>
       <message name="IDS_BRAVE_NEW_TAB_UNDO_REMOVED" desc="Shown when a user wants to undo removing a tile.">Undo</message>
       <message name="IDS_BRAVE_NEW_TAB_CLOSE" desc="Shown when a user wants to close the site removal notification.">Close</message>