Fix the build problem with bpf project

Add the necessary Android.bp file and fix the compile error for the new
bpf project.

Fix the run time restart false alarm in bpf loader.

Bug: 112334572

Test: device boot and dumpsys netd show eBPF object okay, runtime
      restart netd and no bpfloader error showed in logcat.
Change-Id: Iae193bda45e50b7d22479086d6403e3c4fb185c4
diff --git a/Android.bp b/Android.bp
new file mode 100644
index 0000000..ca64e87
--- /dev/null
+++ b/Android.bp
@@ -0,0 +1,17 @@
+cc_defaults {
+    name: "bpf_defaults",
+    cpp_std: "c++17",
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wnullable-to-nonnull-conversion",
+        "-Wthread-safety",
+        "-Wunused-parameter",
+    ],
+    tidy: true,
+    tidy_checks: [
+        "android-*",
+        "cert-*",
+        "clang-analyzer-security*",
+    ],
+}