misc/androidstudio/src: drop the -i flag to avoid writing to a read-only $GOROOT

Gradle plugin failed on Mac due to -i flag trying to update /usr/local/go
Since go 1.10, The old advice to add the -i flag for speed,
as in go build -i or go test -i, is no longer necessary:
builds run just as fast without -i.

Fixes golang/go#25076

Change-Id: Ibddab3ff5961e06c8558f2a83af8a6964d622f40
Reviewed-on: https://go-review.googlesource.com/109144
Reviewed-by: Elias Naur <elias.naur@gmail.com>

misc/androidstudio/src/main/groovy/org/golang/mobile/GobindPlugin.groovy

@@ -215,7 +215,7 @@ class GomobileTask extends BindTask implements OutputFileTask {
 		if (outputFile == null) {
 			outputFile = File.createTempFile("gobind-", ".aar")
 		}
-		def cmd = ["bind", "-i"]
+		def cmd = ["bind"]
 		// Add the generated R and databinding classes to the classpath.
 		if (javaCompile) {
 			def classpath = project.files(javaCompile.classpath, javaCompile.destinationDir)