Adds keyword "default" to the API-linter.

This will fix issue when linting Java 8 default methods on interfaces,
e.g. Ie46a876dcb14b46b8b2584735c106c25655ec6cf.

Test: Manualy tried that the linter no longer gives the error.

Change-Id: I68ade6ba6401439667408076a5454caef77ef72d
diff --git a/tools/apilint/apilint.py b/tools/apilint/apilint.py
index ca2d2e7..6ca59b0 100644
--- a/tools/apilint/apilint.py
+++ b/tools/apilint/apilint.py
@@ -91,7 +91,7 @@
             while r in raw: raw.remove(r)
         self.split = list(raw)
 
-        for r in ["method", "public", "protected", "static", "final", "deprecated", "abstract"]:
+        for r in ["method", "public", "protected", "static", "final", "deprecated", "abstract", "default"]:
             while r in raw: raw.remove(r)
 
         self.typ = raw[0]