HSA contribution is indicated in box 12 of W2 with code W (employer+employee) is added as income to CALIFORNIA state tax.

That's correct.  California does not conform to the federal treatment of HSA contributions and does not permit this amount to be excluded from your income, so it must be added back.

In the CA state return turbotax's Learn More for W2 box 12 code W for California's for says: 

"If your employer contributed money to an HSA on your behalf, that contribution is not taxed by the federal government. However, California considers it taxable income."

However, w2 box 12 code W includes my contribution as well as my employer's.  Does CA not consider employee contributions to an HSA as pre-tax contributions and therefore tax my contributions as well as my employer's?