Revert "use boost tar on linux too"

This reverts commit b98974f.

Author: Flewp

ReactAndroid/build.gradle

@@ -37,7 +37,7 @@ def thirdPartyNdkDir = new File("$buildDir/third-party-ndk")
 def reactNativeRootDir = projectDir.parent
 
 // NOTE(flewp): We want CI machines to also expand a tarball instead of a zip.
-def needsBoostTar = Os.isFamily(Os.FAMILY_MAC) || Os.isFamily(Os.FAMILY_UNIX) || System.getenv("CI")
+def needsBoostTar = Os.isFamily(Os.FAMILY_MAC) || System.getenv("CI")
 def boostExtension = needsBoostTar ? ".tar.gz" : ".zip"
 
 // We put the publishing version from gradle.properties inside ext. so other