Fix/suppress aapt/aapt2 google-explicit-constructor warnings

* Add explicit to conversion constructors/operators
* Use NOLINT or NOLINTNEXTLINE to suppress warnings on intended converters

Bug: 28341362
Test: make with WITH_TIDY=1 DEFAULT_GLOBAL_TIDY_CHECKS=-*,google-explicit-constructor
Change-Id: Ie02101ea7c422e8add535c111a30a2f21ead0ace
diff --git a/tools/aapt2/process/SymbolTable.h b/tools/aapt2/process/SymbolTable.h
index 51a2e373..2d8bd02 100644
--- a/tools/aapt2/process/SymbolTable.h
+++ b/tools/aapt2/process/SymbolTable.h
@@ -71,7 +71,7 @@
     bool is_dynamic = false;
   };
 
-  SymbolTable(NameMangler* mangler);
+  explicit SymbolTable(NameMangler* mangler);
 
   // Overrides the default ISymbolTableDelegate, which allows a custom defined strategy for
   // looking up resources from a set of sources.