[CLATJ#7] ClatCoordinator: select IPv4 address for clatd

Introduce ClatCoordinator to replace netd/ClatdController.
This is a startup commit. Starting clatd needs to prepare local
464xlat ipv4 address, local 464xlat ipv6 address, tun interface,
clat read/write sockets. These will be implemented from this
and followup commits. This commit implements that prepare local
464xlat ipv4 address.

Bug: 212345928
Test: flash and boot
Run "atest ClatCoordinatorTest" in a followup commit.

Change-Id: I486db8aef0181ee1aedd7cd7702f95d5a1cef812
diff --git a/service/Android.bp b/service/Android.bp
index 76f9153..5ba6a00 100644
--- a/service/Android.bp
+++ b/service/Android.bp
@@ -57,12 +57,18 @@
     ],
     srcs: [
         "jni/com_android_server_TestNetworkService.cpp",
+        "jni/com_android_server_connectivity_ClatCoordinator.cpp",
         "jni/onload.cpp",
     ],
     stl: "libc++_static",
     header_libs: [
         "libbase_headers",
     ],
+    static_libs: [
+        "libclat",
+        "libip_checksum",
+        "libnetjniutils",
+    ],
     shared_libs: [
         "liblog",
         "libnativehelper",