Create a timerfd JNI class

The timerfd delivers timer expiration notifications via a file
descriptor, which can be used to implement delayed callbacks.
Create a JNI class to interface with the timerfd system calls.

Bug: 366373064
Test: m
Change-Id: I0ae7a4cf618838e614b2fa4523b55a4d0e8f74e2
diff --git a/service/Android.bp b/service/Android.bp
index 94061a4..e6caf9d 100644
--- a/service/Android.bp
+++ b/service/Android.bp
@@ -90,6 +90,7 @@
     static_libs: [
         "libnet_utils_device_common_bpfjni",
         "libnet_utils_device_common_bpfutils",
+        "libnet_utils_device_common_timerfdjni",
     ],
     shared_libs: [
         "liblog",