Add Android to filename_rules.gypi

BUG=crashpad:30

Change-Id: I62c7cb5ae73a77ac1410de2892648033c80d0d2a
Reviewed-on: https://chromium-review.googlesource.com/405467
Reviewed-by: Robert Sesek <rsesek@chromium.org>

build/filename_rules.gypi

diff --git a/build/filename_rules.gypi b/build/filename_rules.gypi
index 2a1f3fc..1393c47 100644
--- a/build/filename_rules.gypi
+++ b/build/filename_rules.gypi
@@ -16,6 +16,12 @@
         ['exclude', '(^|/)linux/'],
       ],
     }],
+    ['OS!="android"', {
+      'sources/': [
+        ['exclude', '_android(_test)?\\.(h|cc)$'],
+        ['exclude', '(^|/)android/'],
+      ],
+    }],
     ['OS=="win"', {
       'sources/': [
         ['exclude', '_posix(_test)?\\.(h|cc)$'],