assemble_vintf: accept --kernel for manifests.

Add KernelInfo to HalManifest object.

The final verified_assembled_vendor_manifest.xml will contain
<kernel> information for compatibility check during OTA.

Bug: 111125947
Test: build verified_assembled_vendor_manifest.xml

Change-Id: If5a3124b6cbed4da9b2038c30274c223ee52b259
diff --git a/KernelConfigParser.cpp b/KernelConfigParser.cpp
index a0955e2..5713f22 100644
--- a/KernelConfigParser.cpp
+++ b/KernelConfigParser.cpp
@@ -133,5 +133,17 @@
     return err;
 }
 
+status_t KernelConfigParser::processAndFinish(const char* buf, size_t len) {
+    status_t err = process(buf, len);
+    if (err != OK) {
+        return err;
+    }
+    return finish();
+}
+
+status_t KernelConfigParser::processAndFinish(const std::string& content) {
+    return processAndFinish(content.c_str(), content.size());
+}
+
 }  // namespace vintf
 }  // namespace android