how to get a job in google ?

These all skill items have level starting from 0 to anytime, everything on a high demand, but again the exceptional demand is for skill, means that can solve business problem, because only business problem can give you the money. As most of the business have origin from Job Search for Technology Professionals , (dice-com), or See Google Jobs, If you are specifically interested in Google (You may also reach out to your connections via LinkedIn or see what guys are doing at Google) so go there and see type of openings in the different state in USA, that ill give you an idea what to start from any of these :

Added some example :

• Front end  - Pick specific javascript and HTML5 start from there,
• Back end  - Java Stack or Ruby Stack or PHP stack ..you choose,
• Web designing - UI are you talking about ?, Are you passionate on it ?
• Python
• UI/UX
• Django, JS
• Java
• Networking - Talking here TCP/IP ?
• Machine learning...
• Research work

If you are sure to your thoughts then go for it, Above I just told you the way to select the best for you. But you still want that I should suggest you something then go for :

Example ?
1- Front - End - be the father of javascript, Ajax, HTML5 - and be a Visual designer expert or UI expert.

Do not fall in general skill category candidates, where they will continue to negotiate your coding , algorithmic skills, have something different.

Know your enemy and half the battle is won !

Google has a culture of its own for hiring people. They give high priority to whom they bring in.

Google believe in false positive error approach rather than positive-true method.That means, google is okay to NOT hire you and regret upon it rather than, Hiring some idiot and then take the pain in firing him .

So you have to convince google beyond that critical level. 

Investigate how google hiring works?

This can be applied for every company. Read books written upon google. I did my seminar during my college days over GOOGLE. That research introduced me into SEo optimization and i became a SEO expert by accident. Read every book written upon google. Keep yourself updated about companies new hiring . Linkedin is a recommended site for such targeted people hunting. Then check out there career records. Mimic it. Be smart with your approach towards job in google.

Ask Yourself

"ek baar commitment kardi toh apane aapki bhi nahi sunta" That approach is applaudable.But dont waste your time  by commitmenting to each and every thing.

Ask yourself is it the google that has influenced you or rather the pay-scale of crore and above that they pay to new recruit from india? If you had this wish to join google after reading about salary package at google,then your commitment is towards the package,not google.

Google believes in democratizing information. They believe in motto " Don't be evil" Do you synchronize yourself with those visions and motto? ASK YOURSELF.