[LSC] Add LOCAL_LICENSE_KINDS to system/bpf

Added SPDX-license-identifier-Apache-2.0 to:
  Android.bp
  bpfloader/Android.bp
  libbpf_android/Android.bp
  progs/Android.bp

Bug: 68860345
Bug: 151177513
Bug: 151953481

Test: m all

Exempt-From-Owner-Approval: janitorial work
Change-Id: Ia881b61da1755797085916aab5325375c82ed76e

Android.bp

@@ -1,3 +1,20 @@
+package {
+    default_applicable_licenses: ["system_bpf_license"],
+}
+
+// Added automatically by a large-scale-change
+// http://go/android-license-faq
+license {
+    name: "system_bpf_license",
+    visibility: [":__subpackages__"],
+    license_kinds: [
+        "SPDX-license-identifier-Apache-2.0",
+    ],
+    license_text: [
+        "NOTICE",
+    ],
+}
+
 cc_defaults {
     name: "bpf_defaults",
     cflags: [