Sure there is a minSdk="" in AndroidManifest.xml that exists for any Android module, apps or libraries.

As a matter of fact I looked at https://github.com/googleapis/google-http-java-client/blob/master/google-http-client-android/AndroidManifest.xml

and it shows this:
android:minSdkVersion="4"
android:targetSdkVersion="4"

It should read 14 and not 4. I suppose other libraries are affected the same way but I didn't check.