[android] Simplify structure for native files

platform/android/src/log_android.cpp

@@ -0,0 +1,34 @@
+#include <mbgl/platform/log.hpp>
+
+#include <android/log.h>
+
+namespace mbgl {
+
+namespace {
+
+int severityToPriority(EventSeverity severity) {
+    switch(severity) {
+    case EventSeverity::Debug:
+        return ANDROID_LOG_DEBUG;
+
+    case EventSeverity::Info:
+        return ANDROID_LOG_INFO;
+
+    case EventSeverity::Warning:
+        return ANDROID_LOG_WARN;
+
+    case EventSeverity::Error:
+        return ANDROID_LOG_ERROR;
+
+    default:
+        return ANDROID_LOG_VERBOSE;
+    }
+}
+
+} // namespace
+
+void Log::platformRecord(EventSeverity severity, const std::string &msg) {
+    __android_log_print(severityToPriority(severity), "mbgl", "%s", msg.c_str());
+}
+
+}