Make dependency locking configurable

[ccjernigan]

Is your feature request related to a problem? Please describe.

Due to a limitation in Android Studio, dependency locks seem to break builds on Intel devices when dependency locks are enabled https://issuetracker.google.com/issues/236001084

Although we recommend IntelliJ for this project, some contributors might still try to open it with Android Studio. This will also make our configuration consistent with the other ECC Gradle projects.

Describe the solution you'd like

1. Add a new gradle property IS_DEPENDENCY_LOCKING_ENABLED=true and wrap the gradle script configuration for locks with this property.
2. Add documentation that this property is a workaround for this issue. Developers experiencing this issue can then set a global ~/.gradle/gradle.properties IS_DEPENDENCY_LOCKING_ENABLED=false to disable the locks just on their machine.