clang-tidy: Enable bugprone-forward-declaration

Modified code to address issues flagged by
bugprone-forward-declaration-namespace check.

Tested: Build and unit tests passed successfully.

Change-Id: Ied7e54a6aa30d3f8110bcd7036c84b99e7fe6fb8
Signed-off-by: Jayanth Othayoth <ojayanth@gmail.com>
diff --git a/.clang-tidy b/.clang-tidy
index 80de2f6..bfa78f0 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -13,6 +13,7 @@
 bugprone-dangling-handle,
 bugprone-dynamic-static-initializers,
 bugprone-fold-init-type,
+bugprone-forward-declaration-namespace,
 bugprone-forwarding-reference-overload,
 bugprone-implicit-widening-of-multiplication-result,
 bugprone-inaccurate-erase,