Linear phase FIR filter for impulse responses that don't appear symmetric
Your confusion is understandable. 

If you consider the definition of linear phase FIR filter and the associated symmetry conditions on their impulse responses, then you can arrive the conclusion that the first two cases 

$$ h_1[n] = [0,0,0,1,0] $$

and 

$$ h_2[n] = [0,0,0,0,1,0,0,0,0,0,1] $$

are non-symmetric. However, as you use zeros and ones in those impulse responses, it can be seen that the following two new augmented impulse responses are equivalent to those non-symmetric looking ones:

$$ h_3[n] = [0,0,0,1,0,0,0] $$

and 

$$ h_4[n] = [0,0,0,0,1,0,0,0,0,0,1,0,0,0,0] $$

And they are symmetric and linear phase according to the definition as well. This happens because of the zeros and use of ones in a specific way.

However, the following impulse response

$$h_5[n] = [0,0,1,0,0,0,0,1,0,1,0]$$

is not symmetric, is not linear phase and cannot be made linear phase by augmenting with zeros...