Some drivers do not always report the proper info log length
through glGetShaderiv which causes the JNI bindings to return
an empty log string. This change falls back to a length of
512 bytes when the queried length is 0. This is the same
fallback used in libhwui.
Test: CtsOpenGLTest
Bug: 16624915
Change-Id: I86ea52903b280a86305eaaa83eefcf46a7a8d0b4