Docs: Add Security tab to top

Bug: 24908502
Change-Id: If3331bc4ba84a8694bc30cfa81d9dc080e93fa09
diff --git a/tools/droiddoc/templates-sac/components/masthead.cs b/tools/droiddoc/templates-sac/components/masthead.cs
index a8618c0..ee2582f 100644
--- a/tools/droiddoc/templates-sac/components/masthead.cs
+++ b/tools/droiddoc/templates-sac/components/masthead.cs
@@ -255,7 +255,7 @@
           <a href="<?cs var:toroot ?>index.html">
             <img src="<?cs var:toroot ?>assets/images/sac_logo.png"
                 srcset="<?cs var:toroot ?>assets/images/sac_logo@2x.png 2x"
-                width="123" height="25" alt="Android Developers" />
+                width="123" height="25" alt="Android Open Source Project" />
           </a>
           </div>
             <ul class="nav-x col-9">
@@ -266,9 +266,9 @@
                 <li class="devices"><a href="<?cs var:toroot ?>devices/index.html" <?cs
                   if:devices ?>class="selected"<?cs /if ?>
                   >Devices</a></li>
-                <li class="accessories"><a href="<?cs var:toroot ?>accessories/index.html" <?cs
-                  if:accessories ?>class="selected"<?cs /if ?>
-                  >Accessories</a></li>
+                <li class="security"><a href="<?cs var:toroot ?>security/index.html" <?cs
+                  if:security ?>class="selected"<?cs /if ?>
+                  >Security</a></li>
                 <li class="compatibility last"><a href="<?cs var:toroot ?>compatibility/index.html" <?cs
                   if:compatibility ?>class="selected"<?cs /if ?>
                   >Compatibility</a></li>