Deprecate setProperties on ConfigurationFactory

Deprecate `PropertiesConfigurationFactory.setProperties()` since it was
only being used in tests.

Fixes gh-5930

Author: philwebb

spring-boot/src/main/java/org/springframework/boot/bind/PropertiesConfigurationFactory.java

@@ -35,6 +35,7 @@
 import org.springframework.context.MessageSource;
 import org.springframework.context.MessageSourceAware;
 import org.springframework.core.convert.ConversionService;
+import org.springframework.core.env.PropertiesPropertySource;
 import org.springframework.core.env.PropertySources;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
@@ -161,7 +162,10 @@ public void setMessageSource(MessageSource messageSource) {
 	/**
 	 * Set the properties.
 	 * @param properties the properties
+	 * @deprecated as of 1.4 in favor of {@link #setPropertySources(PropertySources)
+	 * setPropertySources} that contains a {@link PropertiesPropertySource}.
 	 */
+	@Deprecated
 	public void setProperties(Properties properties) {
 		this.properties = properties;
 	}

spring-boot/src/test/java/org/springframework/boot/bind/PropertiesConfigurationFactoryMapTests.java

@@ -95,6 +95,7 @@ private Foo createFoo(final String values) throws Exception {
 		return bindFoo(values);
 	}
 
+	@Deprecated
 	private Foo bindFoo(final String values) throws Exception {
 		this.factory.setProperties(PropertiesLoaderUtils
 				.loadProperties(new ByteArrayResource(values.getBytes())));

spring-boot/src/test/java/org/springframework/boot/bind/PropertiesConfigurationFactoryParameterizedTests.java

@@ -102,6 +102,7 @@ private Foo createFoo(final String values) throws Exception {
 		return bindFoo(values);
 	}
 
+	@Deprecated
 	private Foo bindFoo(final String values) throws Exception {
 		Properties properties = PropertiesLoaderUtils
 				.loadProperties(new ByteArrayResource(values.getBytes()));

spring-boot/src/test/java/org/springframework/boot/bind/PropertiesConfigurationFactoryTests.java

@@ -169,6 +169,7 @@ private Foo createFoo(final String values) throws Exception {
 		return bindFoo(values);
 	}
 
+	@Deprecated
 	private Foo bindFoo(final String values) throws Exception {
 		this.factory.setProperties(PropertiesLoaderUtils
 				.loadProperties(new ByteArrayResource(values.getBytes())));