Add OWNERS for libprocessgroup

Test: n/a
Change-Id: I7c069e439cf1d9d26fd5274647567fb1c5575a72
diff --git a/libprocessgroup/OWNERS b/libprocessgroup/OWNERS
new file mode 100644
index 0000000..bfa730a
--- /dev/null
+++ b/libprocessgroup/OWNERS
@@ -0,0 +1,2 @@
+ccross@google.com
+tomcherry@google.com