Install all comp mat to system image

Moved framework_compatibility_matrix.xml module definition
from target/board/Android.mk here because it depends on
compatibility_matrix.*.xml.

Test: m dist
Bug: 69636193

Change-Id: I7480b27756992b47555f6b397925170ae9d1ac22
diff --git a/compatibility_matrices/compatibility_matrix.empty.xml b/compatibility_matrices/compatibility_matrix.empty.xml
new file mode 100644
index 0000000..216f5f1
--- /dev/null
+++ b/compatibility_matrices/compatibility_matrix.empty.xml
@@ -0,0 +1 @@
+<compatibility-matrix version="1.0" type="framework" />