Prepare api manager communication channel for Wallet

[W3-Anjan]

I'm submitting a ...

• feature request
• support request

Expected Behavior

We want to use an api manager so from activity we can call it, as well as we want to give facilities for developers to use the vary same api manager so they can design their own UI and cope up with background data flow.

[W3-MajorArif]

I'v added some required functionalities in the wallet manager class and transferred some code tightly coupled to db/storage to manager class.

[W3-MajorArif]

Task has been completed and pushed.

[W3-MajorArif]

Communication with aidl service has been completed.

[W3-MajorArif]

1. IPC functionality added for Dataplan and Wallet,
2. DataPlanManager and WalletManager created,
3. Observer added for IPC functions.