Modernize codebase by replacing NULL with nullptr

Fixes -Wzero-as-null-pointer-constant warning.

Test: m
Bug: 68236239
Change-Id: I226a0599db4f7c3557e55cade7869d00bd314949
diff --git a/server/NetdNativeService.cpp b/server/NetdNativeService.cpp
index 99c4452..12c78ef 100644
--- a/server/NetdNativeService.cpp
+++ b/server/NetdNativeService.cpp
@@ -70,7 +70,7 @@
 
 #define ENFORCE_DEBUGGABLE() {                              \
     char value[PROPERTY_VALUE_MAX + 1];                     \
-    if (property_get("ro.debuggable", value, NULL) != 1     \
+    if (property_get("ro.debuggable", value, nullptr) != 1  \
             || value[0] != '1') {                           \
         return binder::Status::fromExceptionCode(           \
             binder::Status::EX_SECURITY,                    \