Tombstone Monitor for CVD

Guest side notification for tombstone creation. Host process first pass
now exists. Kernel flags have been utilized to enable or disable the host
and guest tombstone tranmitter and monitor.

Vsock between host and guest now exists and a simple message is set up
to go from the guest to the host on the write and close of a tombstone.

Tombstones are also written out on the host now using unique names. Binary
runs out of product partition with no se policy violations.

Change-Id: Ia3a8132e42ce911aef73177d7b7c7bd7e2c4df76
Bug: 128713152
Test: Treehugger
diff --git a/host_package.mk b/host_package.mk
index f42b9b0..bad6155 100644
--- a/host_package.mk
+++ b/host_package.mk
@@ -40,6 +40,7 @@
     crosvm \
     logcat_receiver \
     config_server \
+    tombstone_receiver \
 
 cvd_host_tests := \
     auto_free_buffer_test \