Soong: support Errorprone javacflags

Add support for an errorprone block in Java modules that accepts
additional javacflags for the errorprone build.

Sample:

    errorprone: {
        javacflags: ["-Xep:EqualsNaN:WARN"],
    },

Bug: 72004718
Test: m RUN_ERROR_PRONE=true
Test: manual - add block with ERROR to a project
Test: androidmk_test
Change-Id: I502248fe76c26aa19102f413af72a7324c35b7f4

androidmk/cmd/androidmk/android.go

@@ -128,6 +128,7 @@ func init() {
 
 			"LOCAL_JAVA_RESOURCE_DIRS":    "java_resource_dirs",
 			"LOCAL_JAVACFLAGS":            "javacflags",
+			"LOCAL_ERROR_PRONE_FLAGS":     "errorprone.javacflags",
 			"LOCAL_DX_FLAGS":              "dxflags",
 			"LOCAL_JAVA_LIBRARIES":        "libs",
 			"LOCAL_STATIC_JAVA_LIBRARIES": "static_libs",

androidmk/cmd/androidmk/androidmk_test.go

@@ -474,6 +474,24 @@ include $(call all-makefiles-under,$(LOCAL_PATH))
 			}
 		`,
 	},
+	{
+		desc: "errorprone options for java library",
+		in: `
+			include $(CLEAR_VARS)
+			LOCAL_ERROR_PRONE_FLAGS := -Xep:AsyncCallableReturnsNull:ERROR -Xep:AsyncFunctionReturnsNull:ERROR
+			include $(BUILD_JAVA_LIBRARY)
+		`,
+		expected: `
+			java_library {
+				errorprone: {
+					javacflags: [
+						"-Xep:AsyncCallableReturnsNull:ERROR",
+						"-Xep:AsyncFunctionReturnsNull:ERROR",
+					],
+				},
+			}
+		`,
+	},
 }
 
 func reformatBlueprint(input string) string {