Add signing command for testing.

Extend the AIDL to allow for signing. This will need to be backed out
before shipping, but it's needed for testing right now.

Add a command to sign a set of files to compos_key_cmd & write the
signature files.

Move compos_key_cmd from virt to compos APEX. (We're definitely going
to need this code in CompOS in some form, so might as well make sure
all the dependencies are available.)

Bug: 190166662
Test: Manual: Sign artifacts, check odsign accepts them.
Change-Id: I25361ed0bee52a9ff13924c77d9378efe8bfd314
diff --git a/compos/compos_key_cmd/Android.bp b/compos/compos_key_cmd/Android.bp
index e03dfdf..460b96f 100644
--- a/compos/compos_key_cmd/Android.bp
+++ b/compos/compos_key_cmd/Android.bp
@@ -5,12 +5,18 @@
 cc_binary {
     name: "compos_key_cmd",
     srcs: ["compos_key_cmd.cpp"],
-    apex_available: ["com.android.virt"],
+    apex_available: ["com.android.compos"],
+
+    static_libs: [
+        "lib_compos_proto",
+    ],
 
     shared_libs: [
         "compos_aidl_interface-ndk_platform",
         "libbase",
         "libbinder_ndk",
         "libcrypto",
+        "libfsverity",
+        "libprotobuf-cpp-lite",
     ],
 }