trusty: Add vendor variant of libtrusty_coverage

We want to add coverage statistics to the trusty-ut-ctrl tool, which is
a vendor binary. Thus we need a vendor variant of libtrusty_coverage.
Merges system libtrusty_test and vendor libtrusty into a single
vendor_available library so that we can add vendor_available to
libtrusty_coverage and make it accessible from vendor tools.

Bug: 175221942
Test: make libtrusty_coverage
Change-Id: I68cc8f1c1580bda8591dbe744e9751474811576d
diff --git a/trusty/coverage/Android.bp b/trusty/coverage/Android.bp
index 3d2caa6..6038d44 100644
--- a/trusty/coverage/Android.bp
+++ b/trusty/coverage/Android.bp
@@ -14,6 +14,7 @@
 
 cc_library {
     name: "libtrusty_coverage",
+    vendor_available: true,
     srcs: [
         "coverage.cpp",
     ],
@@ -21,8 +22,9 @@
         "include",
     ],
     static_libs: [
-        "libtrusty_test",
+        "libtrusty",
     ],
+
     shared_libs: [
         "libbase",
         "liblog",
@@ -36,7 +38,7 @@
     ],
     static_libs: [
         "libtrusty_coverage",
-        "libtrusty_test",
+        "libtrusty",
     ],
     shared_libs: [
         "libbase",