Add libfieldnull static target.

Getting everything setup so jvmti agents can reach libbase can be
tricky. Get libfieldnull building statically.

Test: manual. Install agent
Change-Id: Id889636fd40bc39cca438bbb0d1e678dd0e1110f
diff --git a/tools/jvmti-agents/field-null-percent/Android.bp b/tools/jvmti-agents/field-null-percent/Android.bp
index 26bb1dc..52b4d89 100644
--- a/tools/jvmti-agents/field-null-percent/Android.bp
+++ b/tools/jvmti-agents/field-null-percent/Android.bp
@@ -16,18 +16,13 @@
 
 // Build variants {target,host} x {debug,ndebug} x {32,64}
 cc_defaults {
-    name: "fieldnull-defaults",
-    host_supported: true,
+    name: "fieldnull-base-defaults",
     srcs: ["fieldnull.cc"],
     defaults: ["art_defaults"],
 
     // Note that this tool needs to be built for both 32-bit and 64-bit since it requires
     // to be same ISA as what it is attached to.
     compile_multilib: "both",
-
-    shared_libs: [
-        "libbase",
-    ],
     header_libs: [
         "libopenjdkjvmti_headers",
     ],
@@ -42,6 +37,35 @@
     symlink_preferred_arch: true,
 }
 
+cc_defaults {
+    name: "fieldnull-defaults",
+    host_supported: true,
+    shared_libs: [
+        "libbase",
+    ],
+    defaults: ["fieldnull-base-defaults"],
+}
+
+cc_defaults {
+    name: "fieldnull-static-defaults",
+    host_supported: false,
+    defaults: ["fieldnull-base-defaults"],
+
+    shared_libs: [
+        "liblog",
+    ],
+    static_libs: [
+        "libbase_ndk",
+    ],
+    sdk_version: "current",
+    stl: "c++_static",
+}
+
+cc_library {
+    name: "libfieldnulls",
+    defaults: ["fieldnull-static-defaults"],
+}
+
 art_cc_library {
     name: "libfieldnull",
     defaults: ["fieldnull-defaults"],