[Backport 2.19] Add Eclipse P2 mirror to avoid download.eclipse.org outages (flow-framework) (#1469)

Add Eclipse P2 mirror to avoid download.eclipse.org outages (flow-framework) (#1459)

Signed-off-by: Peter Zhu <zhujiaxi@amazon.com>

Author: peterzhuamazon

formatter/formatting.gradle

@@ -21,7 +21,7 @@ allprojects {
                     '',
                     '\\#java|\\#org.opensearch|\\#org.hamcrest|\\#'
             )
-            eclipse().configFile rootProject.file('formatter/formatterConfig.xml')
+            eclipse().withP2Mirrors(Map.of("https://download.eclipse.org/", "https://ci.opensearch.org/")).configFile rootProject.file('formatter/formatterConfig.xml')
             trimTrailingWhitespace()
             endWithNewline();