build.gradle is secured from decompilation?

Question

It is very easy to decompile the code and code is not secured even with the Proguard.

What I required is to secure "key" in the app. Is build.gradle secured ? can it be decompiled ?

buildConfigField "String", "Key", "\"1234567890\""

Update

as per commonsware's answer I got that it's not secured ? is there any other way I can manage this ?

Answer 1

Is build.gradle secured ?

build.gradle is not packaged into the APK.

The specific Gradle for Android statement you have in your question is adding a field to the code-generated BuildConfig Java class. This is handled like any other Java class from a code obfuscation standpoint.