Update Android build files with license info

The downstream copy of SwiftShader in AOSP has license info changes:
https://android-review.googlesource.com/c/platform/external/swiftshader/+/1576044
This change cherry picks it into the upstream repo.

Also add natsu@ and schuffelen@ to OWNERS to retain their privileges
when we directly roll SwiftShader into AOSP.

Bug: skia:11901
Change-Id: Ibfba7640d0133740c38fc0f00d32fcb5e11f8a11
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/54148
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Macnak <natsu@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Commit-Queue: Nicolas Capens <nicolascapens@google.com>
diff --git a/Android.bp b/Android.bp
index 94c173e..62c46e1 100644
--- a/Android.bp
+++ b/Android.bp
@@ -14,6 +14,43 @@
 // limitations under the License.
 //
 
+package {
+    default_applicable_licenses: ["external_swiftshader_license"],
+}
+
+// Added automatically by a large-scale-change that took the approach of
+// 'apply every license found to every target'. While this makes sure we respect
+// every license restriction, it may not be entirely correct.
+//
+// e.g. GPL in an MIT project might only apply to the contrib/ directory.
+//
+// Please consider splitting the single license below into multiple licenses,
+// taking care not to lose any license_kind information, and overriding the
+// default license using the 'licenses: [...]' property on targets as needed.
+//
+// For unused files, consider creating a 'filegroup' with "//visibility:private"
+// to attach the license to, and including a comment whether the files may be
+// used in the current project.
+//
+// large-scale-change filtered out the below license kinds as false-positives:
+//   SPDX-license-identifier-GPL
+//   SPDX-license-identifier-GPL-3.0
+// http://go/android-license-faq
+license {
+    name: "external_swiftshader_license",
+    visibility: [":__subpackages__"],
+    license_kinds: [
+        "SPDX-license-identifier-Apache-2.0",
+        "SPDX-license-identifier-BSD",
+        "SPDX-license-identifier-MIT",
+        "SPDX-license-identifier-NCSA",
+        "legacy_unencumbered",
+    ],
+    license_text: [
+        "LICENSE.txt",
+    ],
+}
+
 cc_defaults {
     name: "swiftshader_common",