Fix a couple of warnings in the ReactAndroid:hermes-engine build

Summary:
While buildling locally, those two warnings pop up.
- ANDROID_LD being unused by the CMake toolchain. I'm removing it.
- The Download task encountering a weak eTag. I'm updating it:
https://github.com/michel-kraemer/gradle-download-task

Changelog:
[Internal] [Changed] - Fix a couple of warnings in the ReactAndroid:hermes-engine build

Reviewed By: dmytrorykun

Differential Revision: D42738919

fbshipit-source-id: 7bd8785ad5b7431d557e2f8c8876b7c3f7294a43

ReactAndroid/hermes-engine/build.gradle

@@ -62,7 +62,7 @@ task downloadHermes(type: Download) {
     src("https://github.com/facebook/hermes/tarball/${hermesVersion}")
     onlyIfModified(true)
     overwrite(true)
-    useETag(true)
+    useETag("all")
     dest(new File(downloadsDir, "hermes.tar.gz"))
 }
 
@@ -136,7 +136,6 @@ android {
                 arguments "-DHERMES_IS_ANDROID=True"
                 arguments "-DANDROID_STL=c++_shared"
                 arguments "-DANDROID_PIE=True"
-                arguments "-DANDROID_LD=lld"
                 arguments "-DIMPORT_HERMESC=${new File(hermesBuildDir, "ImportHermesc.cmake").toString()}"
                 arguments "-DJSI_DIR=${jsiDir}"
                 arguments "-DHERMES_SLOW_DEBUG=False"