Fix clang-tidy warnings in aapt and aapt2.

* Add explicit keyword to conversion constructors.
* Add NOLINT(implicit) comments for implicit conversion constructors.
Bug: 28341362
* Use const reference type for read-only parameters.
Bug: 30407689
* Use const reference type to avoid unnecessary copy.
Bug: 30413862
Test: build with WITH_TIDY=1

Change-Id: Id6d21961f313a1ad92b15a37fdaa5be9e8ab48e1
diff --git a/tools/aapt/ApkBuilder.h b/tools/aapt/ApkBuilder.h
index 0d7f06b..5d3abc6 100644
--- a/tools/aapt/ApkBuilder.h
+++ b/tools/aapt/ApkBuilder.h
@@ -32,7 +32,7 @@
 
 class ApkBuilder : public android::RefBase {
 public:
-    ApkBuilder(const sp<WeakResourceFilter>& configFilter);
+    explicit ApkBuilder(const sp<WeakResourceFilter>& configFilter);
 
     /**
      * Tells the builder to generate a separate APK for resources that