Go back to BSD grep for now.

PCRE grep isn't POSIX enough (BREs vs EREs).

Bug: http://b/111849261
Bug: https://bugs.exim.org/show_bug.cgi?id=2294
Test: N/A
Change-Id: I3eae7f2c50e2fa65702aba3efea73b915621d16e
diff --git a/Android.bp b/Android.bp
index a857554..9b9b272 100644
--- a/Android.bp
+++ b/Android.bp
@@ -80,7 +80,8 @@
 }
 
 cc_binary {
-    name: "grep",
+    // http://b/111849261 - pcre2grep isn't POSIX enough yet.
+    name: "pcre2grep",
     defaults: ["grep_common"],
 }