chore: Added a top-level Makefile in java-sdk to simplify running tests and linters (#242)

* Added a top-level Makefile in java-sdk to simplify running tests and linters

* added clean and all

---------

Co-authored-by: Anurag Bandyopadhyay <angbpy@gmail.com>

Author: Abishek-Newar

Makefile

@@ -0,0 +1,34 @@
+.PHONY: help test test-integration lint fmt
+
+# Default target when 'make' is run without arguments
+help:
+	@echo "Available targets:"
+	@echo "  test           - Run unit tests"
+	@echo "  test-integration - Run integration tests"
+	@echo "  lint           - Run static analysis and checkstyle"
+	@echo "  fmt            - Auto-format code using Spotless"
+
+# Run unit tests
+test:
+	./gradlew test
+
+# Run integration tests
+test-integration:
+	./gradlew test-integration
+
+# Run static analysis and checkstyle
+lint:
+	./gradlew check
+
+# Auto-format code using Spotless
+fmt:
+	./gradlew spotlessApply
+
+
+# Clean build artifacts
+clean:
+	./gradlew clean
+
+# Run all tests
+all: test lint
+	@echo "All checks completed"