Add copyright file in debian rootfs

the format might be different, but we want rootfs to include license
info

Bug: 374200355
Test: build
Change-Id: I8ac142dd528d881256c17ebe371a53e919f40238
diff --git a/guest/forwarder_guest/Cargo.toml b/guest/forwarder_guest/Cargo.toml
index 65f57cf..ce50e4c 100644
--- a/guest/forwarder_guest/Cargo.toml
+++ b/guest/forwarder_guest/Cargo.toml
@@ -2,6 +2,7 @@
 name = "forwarder_guest"
 version = "0.1.0"
 edition = "2021"
+license = "Apache-2.0"
 
 [dependencies]
 clap = { version = "4.5.19", features = ["derive"] }
diff --git a/guest/forwarder_guest_launcher/Cargo.toml b/guest/forwarder_guest_launcher/Cargo.toml
index 03d3f7f..b7f9eaf 100644
--- a/guest/forwarder_guest_launcher/Cargo.toml
+++ b/guest/forwarder_guest_launcher/Cargo.toml
@@ -2,6 +2,7 @@
 name = "forwarder_guest_launcher"
 version = "0.1.0"
 edition = "2021"
+license = "Apache-2.0"
 
 [dependencies]
 anyhow = "1.0.91"
diff --git a/guest/ip_addr_reporter/Cargo.toml b/guest/ip_addr_reporter/Cargo.toml
index e255eaf..57fc0d3 100644
--- a/guest/ip_addr_reporter/Cargo.toml
+++ b/guest/ip_addr_reporter/Cargo.toml
@@ -2,6 +2,7 @@
 name = "ip_addr_reporter"
 version = "0.1.0"
 edition = "2021"
+license = "Apache-2.0"
 
 [dependencies]
 netdev = "0.31.0"