Add 0BSD support to add3prf.py

This adds the ability to detect and generate the correct METADATA file
for 0BSD licensed crates.

Bug: 317214883
Test: atest --host add3prf_test; Ran against https://crates.io/crates/adler
Change-Id: I064297212dbbcf7f195cde5e0b345f43da9369df
diff --git a/scripts/add3prf_test.py b/scripts/add3prf_test.py
index c6be4c9..80bcfa4 100755
--- a/scripts/add3prf_test.py
+++ b/scripts/add3prf_test.py
@@ -64,6 +64,24 @@
     self.assertEqual(preferred_license.group, add3prf.LicenseGroup.RECIPROCAL)
     self.assertEqual(preferred_license.filename, "LICENSE")
 
+  def test_0bsd_license(self):
+    self.fs.create_file("LICENSE")
+    licenses = add3prf.decide_license_type("0BSD")
+    self.assertEqual(len(licenses), 1)
+    preferred_license = licenses[0]
+    self.assertEqual(preferred_license.type, add3prf.LicenseType.ZERO_BSD)
+    self.assertEqual(preferred_license.group, add3prf.LicenseGroup.PERMISSIVE)
+    self.assertEqual(preferred_license.filename, "LICENSE")
+
+  def test_0bsd_licensefile(self):
+    self.fs.create_file("LICENSE-0BSD")
+    licenses = add3prf.decide_license_type("")
+    self.assertEqual(len(licenses), 1)
+    preferred_license = licenses[0]
+    self.assertEqual(preferred_license.type, add3prf.LicenseType.ZERO_BSD)
+    self.assertEqual(preferred_license.group, add3prf.LicenseGroup.PERMISSIVE)
+    self.assertEqual(preferred_license.filename, "LICENSE-0BSD")
+
 
 class AddModuleLicenseTestCase(fake_filesystem_unittest.TestCase):