Looks more like it could be Coprosma repens 'Variegata' or 'Marble Queen'. A somewhat similar appearance to some of the Euonymus fortunei cultivars and kind of the SoCal equivalent :-) Common name "mirror plant", as it typically has very glossy foliage compared to the more matte finish of the euonymus. Here is a link that might be useful:

I had mirror plant (Coprosma repens) in So. Cal. with it's incrediblely glossy green leaves. Had a Viburnum (don't remember which one) with leatherly leaves that unfortunately was susceptible to spider mite. In hot sun Murraya paniculata always looked good. Natal plums (Carex) are attractive (thorns). Escallonia - shorter hybrids. Grewia. Hebe 'Pattys Purple'. Nandina (looks like bamboo). In shade I used camellias with azaelas - did great. Loropetalum needs a bit of sun protection down south. The local Home Depot will carry what does well in your zone - perhaps some hydrangeas are bred for So. Calif.?

A couple of questions about how you intend to do this. Is the raised planter built in at the base of the garage wall already filled with soil, or if not, does it have a waterproofing membrane at the back side to prevent moisture damage at the wall? You say that the raised brick planter is 2 foot tall, but what is the internal width? You also don't mention the orientation of the wall, whether it faces south/west/east etc. You live in such a mild climate zone, that selecting a plant that could be tall and/or vining and look good year round is really not an issue. If you want to plant in pots behind that wall rather than directly in soil, I would recommend that you have such pots hooked up to automatic drip irrigation, and that the pots should be at least 25 inch diameter by 19 inches tall(a fairly standard pot dimension) to support the size of plants to screen that blank wall. Vines/Espaliers that look good year round in coastal southern California might include things like Coprosma repens with glossy green foliage or one of the colorful foliagecultivars of Coprosma repens such as 'Evening Glow', Grewia occidentalis for deep green fine textured foliage and flat growing habit with showy purple flowers year round, Calliandra tweedii if it faces south or west for showy red flowers, and can easily be trained as an espalier. Trailers to plant in pots above the wall should probably also be picked with drought tolerance in mind, and/or also hooked up to automatic drip irrigation. Easy care trailer for sun might include things like prostrate rosemary, Asparagus densiflorus sprengeri compacta, Convolvulus sabatianus, Juniperus conferta, Pelargonium peltatum. Succulents that trail such as Senecio mandraliscae or Oscularia deltoides, and upright succulents with colorful foliage such as Aeonium arboreum 'Zwartkop' or extra long blooming Aloes such as Aloe 'Johnson's Hybrid', and things like Anigozanthus flavidus cultivars would also thrive in full sun. If you are going to have plants that get big enough to effectively screen the blank wall, and not have them planted in soil, I would suggest that you size the container at 15 gallon or larger, which makes them a bit bulky to move, but are large enough that they roots don't dry out so quickly. Again, automatic drip irrigation would make a huge difference in plant appearance and growth. You may not even have room behind your brick planter wall to squeeze in a 5 gallon sized container, which limits the size/height of plants that will do well in containers. Some really fast growing plants that would also work for you might include things like Asparagus retrofractus, Psoralea pinnata, Cussonia paniculata, Acacia species such as A. covenyi, cultriformis, iteaphylla or merinthophora, Melaleuca incana. Some obvious vine choices for full sun would of course include Bougainvillea or Mandevilla 'Sun Parasol Giant Crimson', along with others such as Dalechampia dioscoreifolia, Passiflora 'Lavender Lady', Petrea volubilis, Podranea ricasoliana, Pandorea jasminoides 'Rosea', Stigmaphyllum ciliatum, Thunbergia alata or T. gregorii, and Thenardia floribunda.

Pretty much what you see..the plant just collapses as its capillary action is shut down by the virus. There is no treating that. Just remove and plant something that is resistant. My best advice,but I don't know for sure that's what you have. When all the other Coprosma's are thriving for you..it could just be a one plant problem. Is the stem at the base girdled(eaten)?..because then the problem is the same- no water getting to the plant - only the cause is roof rats eating the bark at the base. Also- are you sure the emitter closest to that plant isn't clogged?