Export UDP socket option consts on Android

(backport <rust-lang#4619>)
(cherry picked from commit a43bdc3)

Author: hulthe

libc-test/semver/android.txt

@@ -3096,6 +3096,12 @@ TUN_F_USO4
 TUN_F_USO6
 TUN_PKT_STRIP
 TUN_TX_TIMESTAMP
+UDP_CORK
+UDP_ENCAP
+UDP_GRO
+UDP_NO_CHECK6_RX
+UDP_NO_CHECK6_TX
+UDP_SEGMENT
 UINPUT_MAX_NAME_SIZE
 UINPUT_VERSION
 UIO_MAXIOV

src/unix/linux_like/android/mod.rs

@@ -1323,6 +1323,15 @@ pub const SOL_ATALK: c_int = 258;
 pub const SOL_NETROM: c_int = 259;
 pub const SOL_ROSE: c_int = 260;
 
+/* UDP socket options */
+// include/uapi/linux/udp.h
+pub const UDP_CORK: c_int = 1;
+pub const UDP_ENCAP: c_int = 100;
+pub const UDP_NO_CHECK6_TX: c_int = 101;
+pub const UDP_NO_CHECK6_RX: c_int = 102;
+pub const UDP_SEGMENT: c_int = 103;
+pub const UDP_GRO: c_int = 104;
+
 /* DCCP socket options */
 pub const DCCP_SOCKOPT_PACKET_SIZE: c_int = 1;
 pub const DCCP_SOCKOPT_SERVICE: c_int = 2;