Fix a bug where CppFlags should have been Cppflags

Bug: 284009449
Test: unit test and manual build
(cherry picked from https://android-review.googlesource.com/q/commit:93893ba061e774c30a647d42e011838822153511)

Merged-In: I9abb056e6b820414707247d1b19ba6aabffc26ea
Change-Id: I9abb056e6b820414707247d1b19ba6aabffc26ea

bp2build/cc_library_conversion_test.go

@@ -4350,3 +4350,43 @@ cc_library {
 		},
 	})
 }
+
+func TestCcLibraryCppFlagsInProductVariables(t *testing.T) {
+	runCcLibraryTestCase(t, Bp2buildTestCase{
+		Description:                "cc_library cppflags in product variables",
+		ModuleTypeUnderTest:        "cc_library",
+		ModuleTypeUnderTestFactory: cc.LibraryFactory,
+		Blueprint: soongCcLibraryPreamble + `cc_library {
+    name: "a",
+    srcs: ["a.cpp"],
+    cppflags: [
+        "-Wextra",
+        "-DDEBUG_ONLY_CODE=0",
+    ],
+    product_variables: {
+        eng: {
+            cppflags: [
+                "-UDEBUG_ONLY_CODE",
+                "-DDEBUG_ONLY_CODE=1",
+            ],
+        },
+    },
+    include_build_directory: false,
+}
+`,
+		ExpectedBazelTargets: makeCcLibraryTargets("a", AttrNameToString{
+			"cppflags": `[
+        "-Wextra",
+        "-DDEBUG_ONLY_CODE=0",
+    ] + select({
+        "//build/bazel/product_variables:eng": [
+            "-UDEBUG_ONLY_CODE",
+            "-DDEBUG_ONLY_CODE=1",
+        ],
+        "//conditions:default": [],
+    })`,
+			"srcs": `["a.cpp"]`,
+		}),
+	},
+	)
+}

cc/bp2build.go

@@ -517,7 +517,7 @@ func (ca *compilerAttributes) convertProductVariables(ctx android.BazelConversio
 	productVarPropNameToAttribute := map[string]*bazel.StringListAttribute{
 		"Cflags":   &ca.copts,
 		"Asflags":  &ca.asFlags,
-		"CppFlags": &ca.cppFlags,
+		"Cppflags": &ca.cppFlags,
 	}
 	for propName, attr := range productVarPropNameToAttribute {
 		if productConfigProps, exists := productVariableProps[propName]; exists {