graphics: update OWNERS

marissaw@ is leaving. jessehall@ is on a different team. Remove
them and add new owners.

Test: Compiles
Bug: 150462113
Change-Id: I922710de701d3923268591bcb48db3e12acb0500
(cherry picked from commit 88417a586b889eec772e3acab5dffaba18a0e678)
diff --git a/graphics/allocator/2.0/utils/OWNERS b/graphics/allocator/2.0/utils/OWNERS
index 273cb4c..2a56b38 100644
--- a/graphics/allocator/2.0/utils/OWNERS
+++ b/graphics/allocator/2.0/utils/OWNERS
@@ -1,4 +1,4 @@
 # Graphics team
-jessehall@google.com
-marissaw@google.com
+chrisforbes@google.com
 stoza@google.com
+vhau@google.com