This patch ensures that we know which arrays are lists (JsonSchema type
"array") and which are maps (JsonSchema type "object"). We can then
default to array_merge for lists and to array_plus for maps. This seems
clearer than requiring an explicit merge strategy to be declared for all
arrays.
This patch specified a mergeTrategy for some config variables that need
behavior different from the default.
This patch also changes the merging behavior to allow non-array values
to replace arrays and vice versa. It also changes the behavior of
defaults to allow falsy values to override non-falsy defaults.
Bug: T300129
Change-Id: Ia7b0c0250af6a957eac1efb554fb47511f5e093f
